From 8528da672cc093d4dd06732819abc1f7b6b5a46e Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Mon, 8 Sep 2014 00:08:51 -0400 Subject: build: move package sources from src/pkg to src Preparation was in CL 134570043. This CL contains only the effect of 'hg mv src/pkg/* src'. For more about the move, see golang.org/s/go14nopkg. --- src/text/scanner/scanner.go | 693 +++++++++++++++++++++++ src/text/scanner/scanner_test.go | 618 ++++++++++++++++++++ src/text/tabwriter/example_test.go | 38 ++ src/text/tabwriter/tabwriter.go | 558 ++++++++++++++++++ src/text/tabwriter/tabwriter_test.go | 652 +++++++++++++++++++++ src/text/template/doc.go | 405 ++++++++++++++ src/text/template/example_test.go | 71 +++ src/text/template/examplefiles_test.go | 182 ++++++ src/text/template/examplefunc_test.go | 54 ++ src/text/template/exec.go | 842 ++++++++++++++++++++++++++++ src/text/template/exec_test.go | 994 +++++++++++++++++++++++++++++++++ src/text/template/funcs.go | 580 +++++++++++++++++++ src/text/template/helper.go | 108 ++++ src/text/template/multi_test.go | 292 ++++++++++ src/text/template/parse/lex.go | 551 ++++++++++++++++++ src/text/template/parse/lex_test.go | 465 +++++++++++++++ src/text/template/parse/node.go | 834 +++++++++++++++++++++++++++ src/text/template/parse/parse.go | 677 ++++++++++++++++++++++ src/text/template/parse/parse_test.go | 423 ++++++++++++++ src/text/template/template.go | 217 +++++++ src/text/template/testdata/file1.tmpl | 2 + src/text/template/testdata/file2.tmpl | 2 + src/text/template/testdata/tmpl1.tmpl | 3 + src/text/template/testdata/tmpl2.tmpl | 3 + 24 files changed, 9264 insertions(+) create mode 100644 src/text/scanner/scanner.go create mode 100644 src/text/scanner/scanner_test.go create mode 100644 src/text/tabwriter/example_test.go create mode 100644 src/text/tabwriter/tabwriter.go create mode 100644 src/text/tabwriter/tabwriter_test.go create mode 100644 src/text/template/doc.go create mode 100644 src/text/template/example_test.go create mode 100644 src/text/template/examplefiles_test.go create mode 100644 src/text/template/examplefunc_test.go create mode 100644 src/text/template/exec.go create mode 100644 src/text/template/exec_test.go create mode 100644 src/text/template/funcs.go create mode 100644 src/text/template/helper.go create mode 100644 src/text/template/multi_test.go create mode 100644 src/text/template/parse/lex.go create mode 100644 src/text/template/parse/lex_test.go create mode 100644 src/text/template/parse/node.go create mode 100644 src/text/template/parse/parse.go create mode 100644 src/text/template/parse/parse_test.go create mode 100644 src/text/template/template.go create mode 100644 src/text/template/testdata/file1.tmpl create mode 100644 src/text/template/testdata/file2.tmpl create mode 100644 src/text/template/testdata/tmpl1.tmpl create mode 100644 src/text/template/testdata/tmpl2.tmpl (limited to 'src/text') diff --git a/src/text/scanner/scanner.go b/src/text/scanner/scanner.go new file mode 100644 index 000000000..5199ee4fc --- /dev/null +++ b/src/text/scanner/scanner.go @@ -0,0 +1,693 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package scanner provides a scanner and tokenizer for UTF-8-encoded text. +// It takes an io.Reader providing the source, which then can be tokenized +// through repeated calls to the Scan function. For compatibility with +// existing tools, the NUL character is not allowed. If the first character +// in the source is a UTF-8 encoded byte order mark (BOM), it is discarded. +// +// By default, a Scanner skips white space and Go comments and recognizes all +// literals as defined by the Go language specification. It may be +// customized to recognize only a subset of those literals and to recognize +// different identifier and white space characters. +// +// Basic usage pattern: +// +// var s scanner.Scanner +// s.Init(src) +// tok := s.Scan() +// for tok != scanner.EOF { +// // do something with tok +// tok = s.Scan() +// } +// +package scanner + +import ( + "bytes" + "fmt" + "io" + "os" + "unicode" + "unicode/utf8" +) + +// A source position is represented by a Position value. +// A position is valid if Line > 0. +type Position struct { + Filename string // filename, if any + Offset int // byte offset, starting at 0 + Line int // line number, starting at 1 + Column int // column number, starting at 1 (character count per line) +} + +// IsValid returns true if the position is valid. +func (pos *Position) IsValid() bool { return pos.Line > 0 } + +func (pos Position) String() string { + s := pos.Filename + if pos.IsValid() { + if s != "" { + s += ":" + } + s += fmt.Sprintf("%d:%d", pos.Line, pos.Column) + } + if s == "" { + s = "???" + } + return s +} + +// Predefined mode bits to control recognition of tokens. For instance, +// to configure a Scanner such that it only recognizes (Go) identifiers, +// integers, and skips comments, set the Scanner's Mode field to: +// +// ScanIdents | ScanInts | SkipComments +// +// With the exceptions of comments, which are skipped if SkipComments is +// set, unrecognized tokens are not ignored. Instead, the scanner simply +// returns the respective individual characters (or possibly sub-tokens). +// For instance, if the mode is ScanIdents (not ScanStrings), the string +// "foo" is scanned as the token sequence '"' Ident '"'. +// +const ( + ScanIdents = 1 << -Ident + ScanInts = 1 << -Int + ScanFloats = 1 << -Float // includes Ints + ScanChars = 1 << -Char + ScanStrings = 1 << -String + ScanRawStrings = 1 << -RawString + ScanComments = 1 << -Comment + SkipComments = 1 << -skipComment // if set with ScanComments, comments become white space + GoTokens = ScanIdents | ScanFloats | ScanChars | ScanStrings | ScanRawStrings | ScanComments | SkipComments +) + +// The result of Scan is one of the following tokens or a Unicode character. +const ( + EOF = -(iota + 1) + Ident + Int + Float + Char + String + RawString + Comment + skipComment +) + +var tokenString = map[rune]string{ + EOF: "EOF", + Ident: "Ident", + Int: "Int", + Float: "Float", + Char: "Char", + String: "String", + RawString: "RawString", + Comment: "Comment", +} + +// TokenString returns a printable string for a token or Unicode character. +func TokenString(tok rune) string { + if s, found := tokenString[tok]; found { + return s + } + return fmt.Sprintf("%q", string(tok)) +} + +// GoWhitespace is the default value for the Scanner's Whitespace field. +// Its value selects Go's white space characters. +const GoWhitespace = 1<<'\t' | 1<<'\n' | 1<<'\r' | 1<<' ' + +const bufLen = 1024 // at least utf8.UTFMax + +// A Scanner implements reading of Unicode characters and tokens from an io.Reader. +type Scanner struct { + // Input + src io.Reader + + // Source buffer + srcBuf [bufLen + 1]byte // +1 for sentinel for common case of s.next() + srcPos int // reading position (srcBuf index) + srcEnd int // source end (srcBuf index) + + // Source position + srcBufOffset int // byte offset of srcBuf[0] in source + line int // line count + column int // character count + lastLineLen int // length of last line in characters (for correct column reporting) + lastCharLen int // length of last character in bytes + + // Token text buffer + // Typically, token text is stored completely in srcBuf, but in general + // the token text's head may be buffered in tokBuf while the token text's + // tail is stored in srcBuf. + tokBuf bytes.Buffer // token text head that is not in srcBuf anymore + tokPos int // token text tail position (srcBuf index); valid if >= 0 + tokEnd int // token text tail end (srcBuf index) + + // One character look-ahead + ch rune // character before current srcPos + + // Error is called for each error encountered. If no Error + // function is set, the error is reported to os.Stderr. + Error func(s *Scanner, msg string) + + // ErrorCount is incremented by one for each error encountered. + ErrorCount int + + // The Mode field controls which tokens are recognized. For instance, + // to recognize Ints, set the ScanInts bit in Mode. The field may be + // changed at any time. + Mode uint + + // The Whitespace field controls which characters are recognized + // as white space. To recognize a character ch <= ' ' as white space, + // set the ch'th bit in Whitespace (the Scanner's behavior is undefined + // for values ch > ' '). The field may be changed at any time. + Whitespace uint64 + + // IsIdentRune is a predicate controlling the characters accepted + // as the ith rune in an identifier. The set of valid characters + // must not intersect with the set of white space characters. + // If no IsIdentRune function is set, regular Go identifiers are + // accepted instead. The field may be changed at any time. + IsIdentRune func(ch rune, i int) bool + + // Start position of most recently scanned token; set by Scan. + // Calling Init or Next invalidates the position (Line == 0). + // The Filename field is always left untouched by the Scanner. + // If an error is reported (via Error) and Position is invalid, + // the scanner is not inside a token. Call Pos to obtain an error + // position in that case. + Position +} + +// Init initializes a Scanner with a new source and returns s. +// Error is set to nil, ErrorCount is set to 0, Mode is set to GoTokens, +// and Whitespace is set to GoWhitespace. +func (s *Scanner) Init(src io.Reader) *Scanner { + s.src = src + + // initialize source buffer + // (the first call to next() will fill it by calling src.Read) + s.srcBuf[0] = utf8.RuneSelf // sentinel + s.srcPos = 0 + s.srcEnd = 0 + + // initialize source position + s.srcBufOffset = 0 + s.line = 1 + s.column = 0 + s.lastLineLen = 0 + s.lastCharLen = 0 + + // initialize token text buffer + // (required for first call to next()). + s.tokPos = -1 + + // initialize one character look-ahead + s.ch = -1 // no char read yet + + // initialize public fields + s.Error = nil + s.ErrorCount = 0 + s.Mode = GoTokens + s.Whitespace = GoWhitespace + s.Line = 0 // invalidate token position + + return s +} + +// next reads and returns the next Unicode character. It is designed such +// that only a minimal amount of work needs to be done in the common ASCII +// case (one test to check for both ASCII and end-of-buffer, and one test +// to check for newlines). +func (s *Scanner) next() rune { + ch, width := rune(s.srcBuf[s.srcPos]), 1 + + if ch >= utf8.RuneSelf { + // uncommon case: not ASCII or not enough bytes + for s.srcPos+utf8.UTFMax > s.srcEnd && !utf8.FullRune(s.srcBuf[s.srcPos:s.srcEnd]) { + // not enough bytes: read some more, but first + // save away token text if any + if s.tokPos >= 0 { + s.tokBuf.Write(s.srcBuf[s.tokPos:s.srcPos]) + s.tokPos = 0 + // s.tokEnd is set by Scan() + } + // move unread bytes to beginning of buffer + copy(s.srcBuf[0:], s.srcBuf[s.srcPos:s.srcEnd]) + s.srcBufOffset += s.srcPos + // read more bytes + // (an io.Reader must return io.EOF when it reaches + // the end of what it is reading - simply returning + // n == 0 will make this loop retry forever; but the + // error is in the reader implementation in that case) + i := s.srcEnd - s.srcPos + n, err := s.src.Read(s.srcBuf[i:bufLen]) + s.srcPos = 0 + s.srcEnd = i + n + s.srcBuf[s.srcEnd] = utf8.RuneSelf // sentinel + if err != nil { + if err != io.EOF { + s.error(err.Error()) + } + if s.srcEnd == 0 { + if s.lastCharLen > 0 { + // previous character was not EOF + s.column++ + } + s.lastCharLen = 0 + return EOF + } + // If err == EOF, we won't be getting more + // bytes; break to avoid infinite loop. If + // err is something else, we don't know if + // we can get more bytes; thus also break. + break + } + } + // at least one byte + ch = rune(s.srcBuf[s.srcPos]) + if ch >= utf8.RuneSelf { + // uncommon case: not ASCII + ch, width = utf8.DecodeRune(s.srcBuf[s.srcPos:s.srcEnd]) + if ch == utf8.RuneError && width == 1 { + // advance for correct error position + s.srcPos += width + s.lastCharLen = width + s.column++ + s.error("illegal UTF-8 encoding") + return ch + } + } + } + + // advance + s.srcPos += width + s.lastCharLen = width + s.column++ + + // special situations + switch ch { + case 0: + // for compatibility with other tools + s.error("illegal character NUL") + case '\n': + s.line++ + s.lastLineLen = s.column + s.column = 0 + } + + return ch +} + +// Next reads and returns the next Unicode character. +// It returns EOF at the end of the source. It reports +// a read error by calling s.Error, if not nil; otherwise +// it prints an error message to os.Stderr. Next does not +// update the Scanner's Position field; use Pos() to +// get the current position. +func (s *Scanner) Next() rune { + s.tokPos = -1 // don't collect token text + s.Line = 0 // invalidate token position + ch := s.Peek() + s.ch = s.next() + return ch +} + +// Peek returns the next Unicode character in the source without advancing +// the scanner. It returns EOF if the scanner's position is at the last +// character of the source. +func (s *Scanner) Peek() rune { + if s.ch < 0 { + // this code is only run for the very first character + s.ch = s.next() + if s.ch == '\uFEFF' { + s.ch = s.next() // ignore BOM + } + } + return s.ch +} + +func (s *Scanner) error(msg string) { + s.ErrorCount++ + if s.Error != nil { + s.Error(s, msg) + return + } + pos := s.Position + if !pos.IsValid() { + pos = s.Pos() + } + fmt.Fprintf(os.Stderr, "%s: %s\n", pos, msg) +} + +func (s *Scanner) isIdentRune(ch rune, i int) bool { + if s.IsIdentRune != nil { + return s.IsIdentRune(ch, i) + } + return ch == '_' || unicode.IsLetter(ch) || unicode.IsDigit(ch) && i > 0 +} + +func (s *Scanner) scanIdentifier() rune { + // we know the zero'th rune is OK; start scanning at the next one + ch := s.next() + for i := 1; s.isIdentRune(ch, i); i++ { + ch = s.next() + } + return ch +} + +func digitVal(ch rune) int { + switch { + case '0' <= ch && ch <= '9': + return int(ch - '0') + case 'a' <= ch && ch <= 'f': + return int(ch - 'a' + 10) + case 'A' <= ch && ch <= 'F': + return int(ch - 'A' + 10) + } + return 16 // larger than any legal digit val +} + +func isDecimal(ch rune) bool { return '0' <= ch && ch <= '9' } + +func (s *Scanner) scanMantissa(ch rune) rune { + for isDecimal(ch) { + ch = s.next() + } + return ch +} + +func (s *Scanner) scanFraction(ch rune) rune { + if ch == '.' { + ch = s.scanMantissa(s.next()) + } + return ch +} + +func (s *Scanner) scanExponent(ch rune) rune { + if ch == 'e' || ch == 'E' { + ch = s.next() + if ch == '-' || ch == '+' { + ch = s.next() + } + ch = s.scanMantissa(ch) + } + return ch +} + +func (s *Scanner) scanNumber(ch rune) (rune, rune) { + // isDecimal(ch) + if ch == '0' { + // int or float + ch = s.next() + if ch == 'x' || ch == 'X' { + // hexadecimal int + ch = s.next() + hasMantissa := false + for digitVal(ch) < 16 { + ch = s.next() + hasMantissa = true + } + if !hasMantissa { + s.error("illegal hexadecimal number") + } + } else { + // octal int or float + has8or9 := false + for isDecimal(ch) { + if ch > '7' { + has8or9 = true + } + ch = s.next() + } + if s.Mode&ScanFloats != 0 && (ch == '.' || ch == 'e' || ch == 'E') { + // float + ch = s.scanFraction(ch) + ch = s.scanExponent(ch) + return Float, ch + } + // octal int + if has8or9 { + s.error("illegal octal number") + } + } + return Int, ch + } + // decimal int or float + ch = s.scanMantissa(ch) + if s.Mode&ScanFloats != 0 && (ch == '.' || ch == 'e' || ch == 'E') { + // float + ch = s.scanFraction(ch) + ch = s.scanExponent(ch) + return Float, ch + } + return Int, ch +} + +func (s *Scanner) scanDigits(ch rune, base, n int) rune { + for n > 0 && digitVal(ch) < base { + ch = s.next() + n-- + } + if n > 0 { + s.error("illegal char escape") + } + return ch +} + +func (s *Scanner) scanEscape(quote rune) rune { + ch := s.next() // read character after '/' + switch ch { + case 'a', 'b', 'f', 'n', 'r', 't', 'v', '\\', quote: + // nothing to do + ch = s.next() + case '0', '1', '2', '3', '4', '5', '6', '7': + ch = s.scanDigits(ch, 8, 3) + case 'x': + ch = s.scanDigits(s.next(), 16, 2) + case 'u': + ch = s.scanDigits(s.next(), 16, 4) + case 'U': + ch = s.scanDigits(s.next(), 16, 8) + default: + s.error("illegal char escape") + } + return ch +} + +func (s *Scanner) scanString(quote rune) (n int) { + ch := s.next() // read character after quote + for ch != quote { + if ch == '\n' || ch < 0 { + s.error("literal not terminated") + return + } + if ch == '\\' { + ch = s.scanEscape(quote) + } else { + ch = s.next() + } + n++ + } + return +} + +func (s *Scanner) scanRawString() { + ch := s.next() // read character after '`' + for ch != '`' { + if ch < 0 { + s.error("literal not terminated") + return + } + ch = s.next() + } +} + +func (s *Scanner) scanChar() { + if s.scanString('\'') != 1 { + s.error("illegal char literal") + } +} + +func (s *Scanner) scanComment(ch rune) rune { + // ch == '/' || ch == '*' + if ch == '/' { + // line comment + ch = s.next() // read character after "//" + for ch != '\n' && ch >= 0 { + ch = s.next() + } + return ch + } + + // general comment + ch = s.next() // read character after "/*" + for { + if ch < 0 { + s.error("comment not terminated") + break + } + ch0 := ch + ch = s.next() + if ch0 == '*' && ch == '/' { + ch = s.next() + break + } + } + return ch +} + +// Scan reads the next token or Unicode character from source and returns it. +// It only recognizes tokens t for which the respective Mode bit (1<<-t) is set. +// It returns EOF at the end of the source. It reports scanner errors (read and +// token errors) by calling s.Error, if not nil; otherwise it prints an error +// message to os.Stderr. +func (s *Scanner) Scan() rune { + ch := s.Peek() + + // reset token text position + s.tokPos = -1 + s.Line = 0 + +redo: + // skip white space + for s.Whitespace&(1< 0 { + // common case: last character was not a '\n' + s.Line = s.line + s.Column = s.column + } else { + // last character was a '\n' + // (we cannot be at the beginning of the source + // since we have called next() at least once) + s.Line = s.line - 1 + s.Column = s.lastLineLen + } + + // determine token value + tok := ch + switch { + case s.isIdentRune(ch, 0): + if s.Mode&ScanIdents != 0 { + tok = Ident + ch = s.scanIdentifier() + } else { + ch = s.next() + } + case isDecimal(ch): + if s.Mode&(ScanInts|ScanFloats) != 0 { + tok, ch = s.scanNumber(ch) + } else { + ch = s.next() + } + default: + switch ch { + case '"': + if s.Mode&ScanStrings != 0 { + s.scanString('"') + tok = String + } + ch = s.next() + case '\'': + if s.Mode&ScanChars != 0 { + s.scanChar() + tok = Char + } + ch = s.next() + case '.': + ch = s.next() + if isDecimal(ch) && s.Mode&ScanFloats != 0 { + tok = Float + ch = s.scanMantissa(ch) + ch = s.scanExponent(ch) + } + case '/': + ch = s.next() + if (ch == '/' || ch == '*') && s.Mode&ScanComments != 0 { + if s.Mode&SkipComments != 0 { + s.tokPos = -1 // don't collect token text + ch = s.scanComment(ch) + goto redo + } + ch = s.scanComment(ch) + tok = Comment + } + case '`': + if s.Mode&ScanRawStrings != 0 { + s.scanRawString() + tok = String + } + ch = s.next() + default: + ch = s.next() + } + } + + // end of token text + s.tokEnd = s.srcPos - s.lastCharLen + + s.ch = ch + return tok +} + +// Pos returns the position of the character immediately after +// the character or token returned by the last call to Next or Scan. +func (s *Scanner) Pos() (pos Position) { + pos.Filename = s.Filename + pos.Offset = s.srcBufOffset + s.srcPos - s.lastCharLen + switch { + case s.column > 0: + // common case: last character was not a '\n' + pos.Line = s.line + pos.Column = s.column + case s.lastLineLen > 0: + // last character was a '\n' + pos.Line = s.line - 1 + pos.Column = s.lastLineLen + default: + // at the beginning of the source + pos.Line = 1 + pos.Column = 1 + } + return +} + +// TokenText returns the string corresponding to the most recently scanned token. +// Valid after calling Scan(). +func (s *Scanner) TokenText() string { + if s.tokPos < 0 { + // no token text + return "" + } + + if s.tokEnd < 0 { + // if EOF was reached, s.tokEnd is set to -1 (s.srcPos == 0) + s.tokEnd = s.tokPos + } + + if s.tokBuf.Len() == 0 { + // common case: the entire token text is still in srcBuf + return string(s.srcBuf[s.tokPos:s.tokEnd]) + } + + // part of the token text was saved in tokBuf: save the rest in + // tokBuf as well and return its content + s.tokBuf.Write(s.srcBuf[s.tokPos:s.tokEnd]) + s.tokPos = s.tokEnd // ensure idempotency of TokenText() call + return s.tokBuf.String() +} diff --git a/src/text/scanner/scanner_test.go b/src/text/scanner/scanner_test.go new file mode 100644 index 000000000..702fac2b1 --- /dev/null +++ b/src/text/scanner/scanner_test.go @@ -0,0 +1,618 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package scanner + +import ( + "bytes" + "fmt" + "io" + "strings" + "testing" + "unicode/utf8" +) + +// A StringReader delivers its data one string segment at a time via Read. +type StringReader struct { + data []string + step int +} + +func (r *StringReader) Read(p []byte) (n int, err error) { + if r.step < len(r.data) { + s := r.data[r.step] + n = copy(p, s) + r.step++ + } else { + err = io.EOF + } + return +} + +func readRuneSegments(t *testing.T, segments []string) { + got := "" + want := strings.Join(segments, "") + s := new(Scanner).Init(&StringReader{data: segments}) + for { + ch := s.Next() + if ch == EOF { + break + } + got += string(ch) + } + if got != want { + t.Errorf("segments=%v got=%s want=%s", segments, got, want) + } +} + +var segmentList = [][]string{ + {}, + {""}, + {"日", "本語"}, + {"\u65e5", "\u672c", "\u8a9e"}, + {"\U000065e5", " ", "\U0000672c", "\U00008a9e"}, + {"\xe6", "\x97\xa5\xe6", "\x9c\xac\xe8\xaa\x9e"}, + {"Hello", ", ", "World", "!"}, + {"Hello", ", ", "", "World", "!"}, +} + +func TestNext(t *testing.T) { + for _, s := range segmentList { + readRuneSegments(t, s) + } +} + +type token struct { + tok rune + text string +} + +var f100 = "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" + +var tokenList = []token{ + {Comment, "// line comments"}, + {Comment, "//"}, + {Comment, "////"}, + {Comment, "// comment"}, + {Comment, "// /* comment */"}, + {Comment, "// // comment //"}, + {Comment, "//" + f100}, + + {Comment, "// general comments"}, + {Comment, "/**/"}, + {Comment, "/***/"}, + {Comment, "/* comment */"}, + {Comment, "/* // comment */"}, + {Comment, "/* /* comment */"}, + {Comment, "/*\n comment\n*/"}, + {Comment, "/*" + f100 + "*/"}, + + {Comment, "// identifiers"}, + {Ident, "a"}, + {Ident, "a0"}, + {Ident, "foobar"}, + {Ident, "abc123"}, + {Ident, "LGTM"}, + {Ident, "_"}, + {Ident, "_abc123"}, + {Ident, "abc123_"}, + {Ident, "_abc_123_"}, + {Ident, "_äöü"}, + {Ident, "_本"}, + {Ident, "äöü"}, + {Ident, "本"}, + {Ident, "a۰۱۸"}, + {Ident, "foo६४"}, + {Ident, "bar９８７６"}, + {Ident, f100}, + + {Comment, "// decimal ints"}, + {Int, "0"}, + {Int, "1"}, + {Int, "9"}, + {Int, "42"}, + {Int, "1234567890"}, + + {Comment, "// octal ints"}, + {Int, "00"}, + {Int, "01"}, + {Int, "07"}, + {Int, "042"}, + {Int, "01234567"}, + + {Comment, "// hexadecimal ints"}, + {Int, "0x0"}, + {Int, "0x1"}, + {Int, "0xf"}, + {Int, "0x42"}, + {Int, "0x123456789abcDEF"}, + {Int, "0x" + f100}, + {Int, "0X0"}, + {Int, "0X1"}, + {Int, "0XF"}, + {Int, "0X42"}, + {Int, "0X123456789abcDEF"}, + {Int, "0X" + f100}, + + {Comment, "// floats"}, + {Float, "0."}, + {Float, "1."}, + {Float, "42."}, + {Float, "01234567890."}, + {Float, ".0"}, + {Float, ".1"}, + {Float, ".42"}, + {Float, ".0123456789"}, + {Float, "0.0"}, + {Float, "1.0"}, + {Float, "42.0"}, + {Float, "01234567890.0"}, + {Float, "0e0"}, + {Float, "1e0"}, + {Float, "42e0"}, + {Float, "01234567890e0"}, + {Float, "0E0"}, + {Float, "1E0"}, + {Float, "42E0"}, + {Float, "01234567890E0"}, + {Float, "0e+10"}, + {Float, "1e-10"}, + {Float, "42e+10"}, + {Float, "01234567890e-10"}, + {Float, "0E+10"}, + {Float, "1E-10"}, + {Float, "42E+10"}, + {Float, "01234567890E-10"}, + + {Comment, "// chars"}, + {Char, `' '`}, + {Char, `'a'`}, + {Char, `'本'`}, + {Char, `'\a'`}, + {Char, `'\b'`}, + {Char, `'\f'`}, + {Char, `'\n'`}, + {Char, `'\r'`}, + {Char, `'\t'`}, + {Char, `'\v'`}, + {Char, `'\''`}, + {Char, `'\000'`}, + {Char, `'\777'`}, + {Char, `'\x00'`}, + {Char, `'\xff'`}, + {Char, `'\u0000'`}, + {Char, `'\ufA16'`}, + {Char, `'\U00000000'`}, + {Char, `'\U0000ffAB'`}, + + {Comment, "// strings"}, + {String, `" "`}, + {String, `"a"`}, + {String, `"本"`}, + {String, `"\a"`}, + {String, `"\b"`}, + {String, `"\f"`}, + {String, `"\n"`}, + {String, `"\r"`}, + {String, `"\t"`}, + {String, `"\v"`}, + {String, `"\""`}, + {String, `"\000"`}, + {String, `"\777"`}, + {String, `"\x00"`}, + {String, `"\xff"`}, + {String, `"\u0000"`}, + {String, `"\ufA16"`}, + {String, `"\U00000000"`}, + {String, `"\U0000ffAB"`}, + {String, `"` + f100 + `"`}, + + {Comment, "// raw strings"}, + {String, "``"}, + {String, "`\\`"}, + {String, "`" + "\n\n/* foobar */\n\n" + "`"}, + {String, "`" + f100 + "`"}, + + {Comment, "// individual characters"}, + // NUL character is not allowed + {'\x01', "\x01"}, + {' ' - 1, string(' ' - 1)}, + {'+', "+"}, + {'/', "/"}, + {'.', "."}, + {'~', "~"}, + {'(', "("}, +} + +func makeSource(pattern string) *bytes.Buffer { + var buf bytes.Buffer + for _, k := range tokenList { + fmt.Fprintf(&buf, pattern, k.text) + } + return &buf +} + +func checkTok(t *testing.T, s *Scanner, line int, got, want rune, text string) { + if got != want { + t.Fatalf("tok = %s, want %s for %q", TokenString(got), TokenString(want), text) + } + if s.Line != line { + t.Errorf("line = %d, want %d for %q", s.Line, line, text) + } + stext := s.TokenText() + if stext != text { + t.Errorf("text = %q, want %q", stext, text) + } else { + // check idempotency of TokenText() call + stext = s.TokenText() + if stext != text { + t.Errorf("text = %q, want %q (idempotency check)", stext, text) + } + } +} + +func countNewlines(s string) int { + n := 0 + for _, ch := range s { + if ch == '\n' { + n++ + } + } + return n +} + +func testScan(t *testing.T, mode uint) { + s := new(Scanner).Init(makeSource(" \t%s\n")) + s.Mode = mode + tok := s.Scan() + line := 1 + for _, k := range tokenList { + if mode&SkipComments == 0 || k.tok != Comment { + checkTok(t, s, line, tok, k.tok, k.text) + tok = s.Scan() + } + line += countNewlines(k.text) + 1 // each token is on a new line + } + checkTok(t, s, line, tok, EOF, "") +} + +func TestScan(t *testing.T) { + testScan(t, GoTokens) + testScan(t, GoTokens&^SkipComments) +} + +func TestPosition(t *testing.T) { + src := makeSource("\t\t\t\t%s\n") + s := new(Scanner).Init(src) + s.Mode = GoTokens &^ SkipComments + s.Scan() + pos := Position{"", 4, 1, 5} + for _, k := range tokenList { + if s.Offset != pos.Offset { + t.Errorf("offset = %d, want %d for %q", s.Offset, pos.Offset, k.text) + } + if s.Line != pos.Line { + t.Errorf("line = %d, want %d for %q", s.Line, pos.Line, k.text) + } + if s.Column != pos.Column { + t.Errorf("column = %d, want %d for %q", s.Column, pos.Column, k.text) + } + pos.Offset += 4 + len(k.text) + 1 // 4 tabs + token bytes + newline + pos.Line += countNewlines(k.text) + 1 // each token is on a new line + s.Scan() + } + // make sure there were no token-internal errors reported by scanner + if s.ErrorCount != 0 { + t.Errorf("%d errors", s.ErrorCount) + } +} + +func TestScanZeroMode(t *testing.T) { + src := makeSource("%s\n") + str := src.String() + s := new(Scanner).Init(src) + s.Mode = 0 // don't recognize any token classes + s.Whitespace = 0 // don't skip any whitespace + tok := s.Scan() + for i, ch := range str { + if tok != ch { + t.Fatalf("%d. tok = %s, want %s", i, TokenString(tok), TokenString(ch)) + } + tok = s.Scan() + } + if tok != EOF { + t.Fatalf("tok = %s, want EOF", TokenString(tok)) + } + if s.ErrorCount != 0 { + t.Errorf("%d errors", s.ErrorCount) + } +} + +func testScanSelectedMode(t *testing.T, mode uint, class rune) { + src := makeSource("%s\n") + s := new(Scanner).Init(src) + s.Mode = mode + tok := s.Scan() + for tok != EOF { + if tok < 0 && tok != class { + t.Fatalf("tok = %s, want %s", TokenString(tok), TokenString(class)) + } + tok = s.Scan() + } + if s.ErrorCount != 0 { + t.Errorf("%d errors", s.ErrorCount) + } +} + +func TestScanSelectedMask(t *testing.T) { + testScanSelectedMode(t, 0, 0) + testScanSelectedMode(t, ScanIdents, Ident) + // Don't test ScanInts and ScanNumbers since some parts of + // the floats in the source look like (illegal) octal ints + // and ScanNumbers may return either Int or Float. + testScanSelectedMode(t, ScanChars, Char) + testScanSelectedMode(t, ScanStrings, String) + testScanSelectedMode(t, SkipComments, 0) + testScanSelectedMode(t, ScanComments, Comment) +} + +func TestScanCustomIdent(t *testing.T) { + const src = "faab12345 a12b123 a12 3b" + s := new(Scanner).Init(strings.NewReader(src)) + // ident = ( 'a' | 'b' ) { digit } . + // digit = '0' .. '3' . + // with a maximum length of 4 + s.IsIdentRune = func(ch rune, i int) bool { + return i == 0 && (ch == 'a' || ch == 'b') || 0 < i && i < 4 && '0' <= ch && ch <= '3' + } + checkTok(t, s, 1, s.Scan(), 'f', "f") + checkTok(t, s, 1, s.Scan(), Ident, "a") + checkTok(t, s, 1, s.Scan(), Ident, "a") + checkTok(t, s, 1, s.Scan(), Ident, "b123") + checkTok(t, s, 1, s.Scan(), Int, "45") + checkTok(t, s, 1, s.Scan(), Ident, "a12") + checkTok(t, s, 1, s.Scan(), Ident, "b123") + checkTok(t, s, 1, s.Scan(), Ident, "a12") + checkTok(t, s, 1, s.Scan(), Int, "3") + checkTok(t, s, 1, s.Scan(), Ident, "b") + checkTok(t, s, 1, s.Scan(), EOF, "") +} + +func TestScanNext(t *testing.T) { + const BOM = '\uFEFF' + BOMs := string(BOM) + s := new(Scanner).Init(strings.NewReader(BOMs + "if a == bcd /* com" + BOMs + "ment */ {\n\ta += c\n}" + BOMs + "// line comment ending in eof")) + checkTok(t, s, 1, s.Scan(), Ident, "if") // the first BOM is ignored + checkTok(t, s, 1, s.Scan(), Ident, "a") + checkTok(t, s, 1, s.Scan(), '=', "=") + checkTok(t, s, 0, s.Next(), '=', "") + checkTok(t, s, 0, s.Next(), ' ', "") + checkTok(t, s, 0, s.Next(), 'b', "") + checkTok(t, s, 1, s.Scan(), Ident, "cd") + checkTok(t, s, 1, s.Scan(), '{', "{") + checkTok(t, s, 2, s.Scan(), Ident, "a") + checkTok(t, s, 2, s.Scan(), '+', "+") + checkTok(t, s, 0, s.Next(), '=', "") + checkTok(t, s, 2, s.Scan(), Ident, "c") + checkTok(t, s, 3, s.Scan(), '}', "}") + checkTok(t, s, 3, s.Scan(), BOM, BOMs) + checkTok(t, s, 3, s.Scan(), -1, "") + if s.ErrorCount != 0 { + t.Errorf("%d errors", s.ErrorCount) + } +} + +func TestScanWhitespace(t *testing.T) { + var buf bytes.Buffer + var ws uint64 + // start at 1, NUL character is not allowed + for ch := byte(1); ch < ' '; ch++ { + buf.WriteByte(ch) + ws |= 1 << ch + } + const orig = 'x' + buf.WriteByte(orig) + + s := new(Scanner).Init(&buf) + s.Mode = 0 + s.Whitespace = ws + tok := s.Scan() + if tok != orig { + t.Errorf("tok = %s, want %s", TokenString(tok), TokenString(orig)) + } +} + +func testError(t *testing.T, src, pos, msg string, tok rune) { + s := new(Scanner).Init(strings.NewReader(src)) + errorCalled := false + s.Error = func(s *Scanner, m string) { + if !errorCalled { + // only look at first error + if p := s.Pos().String(); p != pos { + t.Errorf("pos = %q, want %q for %q", p, pos, src) + } + if m != msg { + t.Errorf("msg = %q, want %q for %q", m, msg, src) + } + errorCalled = true + } + } + tk := s.Scan() + if tk != tok { + t.Errorf("tok = %s, want %s for %q", TokenString(tk), TokenString(tok), src) + } + if !errorCalled { + t.Errorf("error handler not called for %q", src) + } + if s.ErrorCount == 0 { + t.Errorf("count = %d, want > 0 for %q", s.ErrorCount, src) + } +} + +func TestError(t *testing.T) { + testError(t, "\x00", "1:1", "illegal character NUL", 0) + testError(t, "\x80", "1:1", "illegal UTF-8 encoding", utf8.RuneError) + testError(t, "\xff", "1:1", "illegal UTF-8 encoding", utf8.RuneError) + + testError(t, "a\x00", "1:2", "illegal character NUL", Ident) + testError(t, "ab\x80", "1:3", "illegal UTF-8 encoding", Ident) + testError(t, "abc\xff", "1:4", "illegal UTF-8 encoding", Ident) + + testError(t, `"a`+"\x00", "1:3", "illegal character NUL", String) + testError(t, `"ab`+"\x80", "1:4", "illegal UTF-8 encoding", String) + testError(t, `"abc`+"\xff", "1:5", "illegal UTF-8 encoding", String) + + testError(t, "`a"+"\x00", "1:3", "illegal character NUL", String) + testError(t, "`ab"+"\x80", "1:4", "illegal UTF-8 encoding", String) + testError(t, "`abc"+"\xff", "1:5", "illegal UTF-8 encoding", String) + + testError(t, `'\"'`, "1:3", "illegal char escape", Char) + testError(t, `"\'"`, "1:3", "illegal char escape", String) + + testError(t, `01238`, "1:6", "illegal octal number", Int) + testError(t, `01238123`, "1:9", "illegal octal number", Int) + testError(t, `0x`, "1:3", "illegal hexadecimal number", Int) + testError(t, `0xg`, "1:3", "illegal hexadecimal number", Int) + testError(t, `'aa'`, "1:4", "illegal char literal", Char) + + testError(t, `'`, "1:2", "literal not terminated", Char) + testError(t, `'`+"\n", "1:2", "literal not terminated", Char) + testError(t, `"abc`, "1:5", "literal not terminated", String) + testError(t, `"abc`+"\n", "1:5", "literal not terminated", String) + testError(t, "`abc\n", "2:1", "literal not terminated", String) + testError(t, `/*/`, "1:4", "comment not terminated", EOF) +} + +// An errReader returns (0, err) where err is not io.EOF. +type errReader struct{} + +func (errReader) Read(b []byte) (int, error) { + return 0, io.ErrNoProgress // some error that is not io.EOF +} + +func TestIOError(t *testing.T) { + s := new(Scanner).Init(errReader{}) + errorCalled := false + s.Error = func(s *Scanner, msg string) { + if !errorCalled { + if want := io.ErrNoProgress.Error(); msg != want { + t.Errorf("msg = %q, want %q", msg, want) + } + errorCalled = true + } + } + tok := s.Scan() + if tok != EOF { + t.Errorf("tok = %s, want EOF", TokenString(tok)) + } + if !errorCalled { + t.Errorf("error handler not called") + } +} + +func checkPos(t *testing.T, got, want Position) { + if got.Offset != want.Offset || got.Line != want.Line || got.Column != want.Column { + t.Errorf("got offset, line, column = %d, %d, %d; want %d, %d, %d", + got.Offset, got.Line, got.Column, want.Offset, want.Line, want.Column) + } +} + +func checkNextPos(t *testing.T, s *Scanner, offset, line, column int, char rune) { + if ch := s.Next(); ch != char { + t.Errorf("ch = %s, want %s", TokenString(ch), TokenString(char)) + } + want := Position{Offset: offset, Line: line, Column: column} + checkPos(t, s.Pos(), want) +} + +func checkScanPos(t *testing.T, s *Scanner, offset, line, column int, char rune) { + want := Position{Offset: offset, Line: line, Column: column} + checkPos(t, s.Pos(), want) + if ch := s.Scan(); ch != char { + t.Errorf("ch = %s, want %s", TokenString(ch), TokenString(char)) + if string(ch) != s.TokenText() { + t.Errorf("tok = %q, want %q", s.TokenText(), string(ch)) + } + } + checkPos(t, s.Position, want) +} + +func TestPos(t *testing.T) { + // corner case: empty source + s := new(Scanner).Init(strings.NewReader("")) + checkPos(t, s.Pos(), Position{Offset: 0, Line: 1, Column: 1}) + s.Peek() // peek doesn't affect the position + checkPos(t, s.Pos(), Position{Offset: 0, Line: 1, Column: 1}) + + // corner case: source with only a newline + s = new(Scanner).Init(strings.NewReader("\n")) + checkPos(t, s.Pos(), Position{Offset: 0, Line: 1, Column: 1}) + checkNextPos(t, s, 1, 2, 1, '\n') + // after EOF position doesn't change + for i := 10; i > 0; i-- { + checkScanPos(t, s, 1, 2, 1, EOF) + } + if s.ErrorCount != 0 { + t.Errorf("%d errors", s.ErrorCount) + } + + // corner case: source with only a single character + s = new(Scanner).Init(strings.NewReader("本")) + checkPos(t, s.Pos(), Position{Offset: 0, Line: 1, Column: 1}) + checkNextPos(t, s, 3, 1, 2, '本') + // after EOF position doesn't change + for i := 10; i > 0; i-- { + checkScanPos(t, s, 3, 1, 2, EOF) + } + if s.ErrorCount != 0 { + t.Errorf("%d errors", s.ErrorCount) + } + + // positions after calling Next + s = new(Scanner).Init(strings.NewReader(" foo६४ \n\n本語\n")) + checkNextPos(t, s, 1, 1, 2, ' ') + s.Peek() // peek doesn't affect the position + checkNextPos(t, s, 2, 1, 3, ' ') + checkNextPos(t, s, 3, 1, 4, 'f') + checkNextPos(t, s, 4, 1, 5, 'o') + checkNextPos(t, s, 5, 1, 6, 'o') + checkNextPos(t, s, 8, 1, 7, '६') + checkNextPos(t, s, 11, 1, 8, '४') + checkNextPos(t, s, 12, 1, 9, ' ') + checkNextPos(t, s, 13, 1, 10, ' ') + checkNextPos(t, s, 14, 2, 1, '\n') + checkNextPos(t, s, 15, 3, 1, '\n') + checkNextPos(t, s, 18, 3, 2, '本') + checkNextPos(t, s, 21, 3, 3, '語') + checkNextPos(t, s, 22, 4, 1, '\n') + // after EOF position doesn't change + for i := 10; i > 0; i-- { + checkScanPos(t, s, 22, 4, 1, EOF) + } + if s.ErrorCount != 0 { + t.Errorf("%d errors", s.ErrorCount) + } + + // positions after calling Scan + s = new(Scanner).Init(strings.NewReader("abc\n本語\n\nx")) + s.Mode = 0 + s.Whitespace = 0 + checkScanPos(t, s, 0, 1, 1, 'a') + s.Peek() // peek doesn't affect the position + checkScanPos(t, s, 1, 1, 2, 'b') + checkScanPos(t, s, 2, 1, 3, 'c') + checkScanPos(t, s, 3, 1, 4, '\n') + checkScanPos(t, s, 4, 2, 1, '本') + checkScanPos(t, s, 7, 2, 2, '語') + checkScanPos(t, s, 10, 2, 3, '\n') + checkScanPos(t, s, 11, 3, 1, '\n') + checkScanPos(t, s, 12, 4, 1, 'x') + // after EOF position doesn't change + for i := 10; i > 0; i-- { + checkScanPos(t, s, 13, 4, 2, EOF) + } + if s.ErrorCount != 0 { + t.Errorf("%d errors", s.ErrorCount) + } +} diff --git a/src/text/tabwriter/example_test.go b/src/text/tabwriter/example_test.go new file mode 100644 index 000000000..20443cb1f --- /dev/null +++ b/src/text/tabwriter/example_test.go @@ -0,0 +1,38 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package tabwriter_test + +import ( + "fmt" + "os" + "text/tabwriter" +) + +func ExampleWriter_Init() { + w := new(tabwriter.Writer) + + // Format in tab-separated columns with a tab stop of 8. + w.Init(os.Stdout, 0, 8, 0, '\t', 0) + fmt.Fprintln(w, "a\tb\tc\td\t.") + fmt.Fprintln(w, "123\t12345\t1234567\t123456789\t.") + fmt.Fprintln(w) + w.Flush() + + // Format right-aligned in space-separated columns of minimal width 5 + // and at least one blank of padding (so wider column entries do not + // touch each other). + w.Init(os.Stdout, 5, 0, 1, ' ', tabwriter.AlignRight) + fmt.Fprintln(w, "a\tb\tc\td\t.") + fmt.Fprintln(w, "123\t12345\t1234567\t123456789\t.") + fmt.Fprintln(w) + w.Flush() + + // output: + // a b c d . + // 123 12345 1234567 123456789 . + // + // a b c d. + // 123 12345 1234567 123456789. +} diff --git a/src/text/tabwriter/tabwriter.go b/src/text/tabwriter/tabwriter.go new file mode 100644 index 000000000..c0c32d5de --- /dev/null +++ b/src/text/tabwriter/tabwriter.go @@ -0,0 +1,558 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package tabwriter implements a write filter (tabwriter.Writer) that +// translates tabbed columns in input into properly aligned text. +// +// The package is using the Elastic Tabstops algorithm described at +// http://nickgravgaard.com/elastictabstops/index.html. +// +package tabwriter + +import ( + "bytes" + "io" + "unicode/utf8" +) + +// ---------------------------------------------------------------------------- +// Filter implementation + +// A cell represents a segment of text terminated by tabs or line breaks. +// The text itself is stored in a separate buffer; cell only describes the +// segment's size in bytes, its width in runes, and whether it's an htab +// ('\t') terminated cell. +// +type cell struct { + size int // cell size in bytes + width int // cell width in runes + htab bool // true if the cell is terminated by an htab ('\t') +} + +// A Writer is a filter that inserts padding around tab-delimited +// columns in its input to align them in the output. +// +// The Writer treats incoming bytes as UTF-8 encoded text consisting +// of cells terminated by (horizontal or vertical) tabs or line +// breaks (newline or formfeed characters). Cells in adjacent lines +// constitute a column. The Writer inserts padding as needed to +// make all cells in a column have the same width, effectively +// aligning the columns. It assumes that all characters have the +// same width except for tabs for which a tabwidth must be specified. +// Note that cells are tab-terminated, not tab-separated: trailing +// non-tab text at the end of a line does not form a column cell. +// +// The Writer assumes that all Unicode code points have the same width; +// this may not be true in some fonts. +// +// If DiscardEmptyColumns is set, empty columns that are terminated +// entirely by vertical (or "soft") tabs are discarded. Columns +// terminated by horizontal (or "hard") tabs are not affected by +// this flag. +// +// If a Writer is configured to filter HTML, HTML tags and entities +// are passed through. The widths of tags and entities are +// assumed to be zero (tags) and one (entities) for formatting purposes. +// +// A segment of text may be escaped by bracketing it with Escape +// characters. The tabwriter passes escaped text segments through +// unchanged. In particular, it does not interpret any tabs or line +// breaks within the segment. If the StripEscape flag is set, the +// Escape characters are stripped from the output; otherwise they +// are passed through as well. For the purpose of formatting, the +// width of the escaped text is always computed excluding the Escape +// characters. +// +// The formfeed character ('\f') acts like a newline but it also +// terminates all columns in the current line (effectively calling +// Flush). Cells in the next line start new columns. Unless found +// inside an HTML tag or inside an escaped text segment, formfeed +// characters appear as newlines in the output. +// +// The Writer must buffer input internally, because proper spacing +// of one line may depend on the cells in future lines. Clients must +// call Flush when done calling Write. +// +type Writer struct { + // configuration + output io.Writer + minwidth int + tabwidth int + padding int + padbytes [8]byte + flags uint + + // current state + buf bytes.Buffer // collected text excluding tabs or line breaks + pos int // buffer position up to which cell.width of incomplete cell has been computed + cell cell // current incomplete cell; cell.width is up to buf[pos] excluding ignored sections + endChar byte // terminating char of escaped sequence (Escape for escapes, '>', ';' for HTML tags/entities, or 0) + lines [][]cell // list of lines; each line is a list of cells + widths []int // list of column widths in runes - re-used during formatting +} + +func (b *Writer) addLine() { b.lines = append(b.lines, []cell{}) } + +// Reset the current state. +func (b *Writer) reset() { + b.buf.Reset() + b.pos = 0 + b.cell = cell{} + b.endChar = 0 + b.lines = b.lines[0:0] + b.widths = b.widths[0:0] + b.addLine() +} + +// Internal representation (current state): +// +// - all text written is appended to buf; tabs and line breaks are stripped away +// - at any given time there is a (possibly empty) incomplete cell at the end +// (the cell starts after a tab or line break) +// - cell.size is the number of bytes belonging to the cell so far +// - cell.width is text width in runes of that cell from the start of the cell to +// position pos; html tags and entities are excluded from this width if html +// filtering is enabled +// - the sizes and widths of processed text are kept in the lines list +// which contains a list of cells for each line +// - the widths list is a temporary list with current widths used during +// formatting; it is kept in Writer because it's re-used +// +// |<---------- size ---------->| +// | | +// |<- width ->|<- ignored ->| | +// | | | | +// [---processed---tab------------......] +// ^ ^ ^ +// | | | +// buf start of incomplete cell pos + +// Formatting can be controlled with these flags. +const ( + // Ignore html tags and treat entities (starting with '&' + // and ending in ';') as single characters (width = 1). + FilterHTML uint = 1 << iota + + // Strip Escape characters bracketing escaped text segments + // instead of passing them through unchanged with the text. + StripEscape + + // Force right-alignment of cell content. + // Default is left-alignment. + AlignRight + + // Handle empty columns as if they were not present in + // the input in the first place. + DiscardEmptyColumns + + // Always use tabs for indentation columns (i.e., padding of + // leading empty cells on the left) independent of padchar. + TabIndent + + // Print a vertical bar ('|') between columns (after formatting). + // Discarded columns appear as zero-width columns ("||"). + Debug +) + +// A Writer must be initialized with a call to Init. The first parameter (output) +// specifies the filter output. The remaining parameters control the formatting: +// +// minwidth minimal cell width including any padding +// tabwidth width of tab characters (equivalent number of spaces) +// padding padding added to a cell before computing its width +// padchar ASCII char used for padding +// if padchar == '\t', the Writer will assume that the +// width of a '\t' in the formatted output is tabwidth, +// and cells are left-aligned independent of align_left +// (for correct-looking results, tabwidth must correspond +// to the tab width in the viewer displaying the result) +// flags formatting control +// +func (b *Writer) Init(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *Writer { + if minwidth < 0 || tabwidth < 0 || padding < 0 { + panic("negative minwidth, tabwidth, or padding") + } + b.output = output + b.minwidth = minwidth + b.tabwidth = tabwidth + b.padding = padding + for i := range b.padbytes { + b.padbytes[i] = padchar + } + if padchar == '\t' { + // tab padding enforces left-alignment + flags &^= AlignRight + } + b.flags = flags + + b.reset() + + return b +} + +// debugging support (keep code around) +func (b *Writer) dump() { + pos := 0 + for i, line := range b.lines { + print("(", i, ") ") + for _, c := range line { + print("[", string(b.buf.Bytes()[pos:pos+c.size]), "]") + pos += c.size + } + print("\n") + } + print("\n") +} + +// local error wrapper so we can distinguish errors we want to return +// as errors from genuine panics (which we don't want to return as errors) +type osError struct { + err error +} + +func (b *Writer) write0(buf []byte) { + n, err := b.output.Write(buf) + if n != len(buf) && err == nil { + err = io.ErrShortWrite + } + if err != nil { + panic(osError{err}) + } +} + +func (b *Writer) writeN(src []byte, n int) { + for n > len(src) { + b.write0(src) + n -= len(src) + } + b.write0(src[0:n]) +} + +var ( + newline = []byte{'\n'} + tabs = []byte("\t\t\t\t\t\t\t\t") +) + +func (b *Writer) writePadding(textw, cellw int, useTabs bool) { + if b.padbytes[0] == '\t' || useTabs { + // padding is done with tabs + if b.tabwidth == 0 { + return // tabs have no width - can't do any padding + } + // make cellw the smallest multiple of b.tabwidth + cellw = (cellw + b.tabwidth - 1) / b.tabwidth * b.tabwidth + n := cellw - textw // amount of padding + if n < 0 { + panic("internal error") + } + b.writeN(tabs, (n+b.tabwidth-1)/b.tabwidth) + return + } + + // padding is done with non-tab characters + b.writeN(b.padbytes[0:], cellw-textw) +} + +var vbar = []byte{'|'} + +func (b *Writer) writeLines(pos0 int, line0, line1 int) (pos int) { + pos = pos0 + for i := line0; i < line1; i++ { + line := b.lines[i] + + // if TabIndent is set, use tabs to pad leading empty cells + useTabs := b.flags&TabIndent != 0 + + for j, c := range line { + if j > 0 && b.flags&Debug != 0 { + // indicate column break + b.write0(vbar) + } + + if c.size == 0 { + // empty cell + if j < len(b.widths) { + b.writePadding(c.width, b.widths[j], useTabs) + } + } else { + // non-empty cell + useTabs = false + if b.flags&AlignRight == 0 { // align left + b.write0(b.buf.Bytes()[pos : pos+c.size]) + pos += c.size + if j < len(b.widths) { + b.writePadding(c.width, b.widths[j], false) + } + } else { // align right + if j < len(b.widths) { + b.writePadding(c.width, b.widths[j], false) + } + b.write0(b.buf.Bytes()[pos : pos+c.size]) + pos += c.size + } + } + } + + if i+1 == len(b.lines) { + // last buffered line - we don't have a newline, so just write + // any outstanding buffered data + b.write0(b.buf.Bytes()[pos : pos+b.cell.size]) + pos += b.cell.size + } else { + // not the last line - write newline + b.write0(newline) + } + } + return +} + +// Format the text between line0 and line1 (excluding line1); pos +// is the buffer position corresponding to the beginning of line0. +// Returns the buffer position corresponding to the beginning of +// line1 and an error, if any. +// +func (b *Writer) format(pos0 int, line0, line1 int) (pos int) { + pos = pos0 + column := len(b.widths) + for this := line0; this < line1; this++ { + line := b.lines[this] + + if column < len(line)-1 { + // cell exists in this column => this line + // has more cells than the previous line + // (the last cell per line is ignored because cells are + // tab-terminated; the last cell per line describes the + // text before the newline/formfeed and does not belong + // to a column) + + // print unprinted lines until beginning of block + pos = b.writeLines(pos, line0, this) + line0 = this + + // column block begin + width := b.minwidth // minimal column width + discardable := true // true if all cells in this column are empty and "soft" + for ; this < line1; this++ { + line = b.lines[this] + if column < len(line)-1 { + // cell exists in this column + c := line[column] + // update width + if w := c.width + b.padding; w > width { + width = w + } + // update discardable + if c.width > 0 || c.htab { + discardable = false + } + } else { + break + } + } + // column block end + + // discard empty columns if necessary + if discardable && b.flags&DiscardEmptyColumns != 0 { + width = 0 + } + + // format and print all columns to the right of this column + // (we know the widths of this column and all columns to the left) + b.widths = append(b.widths, width) // push width + pos = b.format(pos, line0, this) + b.widths = b.widths[0 : len(b.widths)-1] // pop width + line0 = this + } + } + + // print unprinted lines until end + return b.writeLines(pos, line0, line1) +} + +// Append text to current cell. +func (b *Writer) append(text []byte) { + b.buf.Write(text) + b.cell.size += len(text) +} + +// Update the cell width. +func (b *Writer) updateWidth() { + b.cell.width += utf8.RuneCount(b.buf.Bytes()[b.pos:b.buf.Len()]) + b.pos = b.buf.Len() +} + +// To escape a text segment, bracket it with Escape characters. +// For instance, the tab in this string "Ignore this tab: \xff\t\xff" +// does not terminate a cell and constitutes a single character of +// width one for formatting purposes. +// +// The value 0xff was chosen because it cannot appear in a valid UTF-8 sequence. +// +const Escape = '\xff' + +// Start escaped mode. +func (b *Writer) startEscape(ch byte) { + switch ch { + case Escape: + b.endChar = Escape + case '<': + b.endChar = '>' + case '&': + b.endChar = ';' + } +} + +// Terminate escaped mode. If the escaped text was an HTML tag, its width +// is assumed to be zero for formatting purposes; if it was an HTML entity, +// its width is assumed to be one. In all other cases, the width is the +// unicode width of the text. +// +func (b *Writer) endEscape() { + switch b.endChar { + case Escape: + b.updateWidth() + if b.flags&StripEscape == 0 { + b.cell.width -= 2 // don't count the Escape chars + } + case '>': // tag of zero width + case ';': + b.cell.width++ // entity, count as one rune + } + b.pos = b.buf.Len() + b.endChar = 0 +} + +// Terminate the current cell by adding it to the list of cells of the +// current line. Returns the number of cells in that line. +// +func (b *Writer) terminateCell(htab bool) int { + b.cell.htab = htab + line := &b.lines[len(b.lines)-1] + *line = append(*line, b.cell) + b.cell = cell{} + return len(*line) +} + +func handlePanic(err *error, op string) { + if e := recover(); e != nil { + if nerr, ok := e.(osError); ok { + *err = nerr.err + return + } + panic("tabwriter: panic during " + op) + } +} + +// Flush should be called after the last call to Write to ensure +// that any data buffered in the Writer is written to output. Any +// incomplete escape sequence at the end is considered +// complete for formatting purposes. +// +func (b *Writer) Flush() (err error) { + defer b.reset() // even in the presence of errors + defer handlePanic(&err, "Flush") + + // add current cell if not empty + if b.cell.size > 0 { + if b.endChar != 0 { + // inside escape - terminate it even if incomplete + b.endEscape() + } + b.terminateCell(false) + } + + // format contents of buffer + b.format(0, 0, len(b.lines)) + + return +} + +var hbar = []byte("---\n") + +// Write writes buf to the writer b. +// The only errors returned are ones encountered +// while writing to the underlying output stream. +// +func (b *Writer) Write(buf []byte) (n int, err error) { + defer handlePanic(&err, "Write") + + // split text into cells + n = 0 + for i, ch := range buf { + if b.endChar == 0 { + // outside escape + switch ch { + case '\t', '\v', '\n', '\f': + // end of cell + b.append(buf[n:i]) + b.updateWidth() + n = i + 1 // ch consumed + ncells := b.terminateCell(ch == '\t') + if ch == '\n' || ch == '\f' { + // terminate line + b.addLine() + if ch == '\f' || ncells == 1 { + // A '\f' always forces a flush. Otherwise, if the previous + // line has only one cell which does not have an impact on + // the formatting of the following lines (the last cell per + // line is ignored by format()), thus we can flush the + // Writer contents. + if err = b.Flush(); err != nil { + return + } + if ch == '\f' && b.flags&Debug != 0 { + // indicate section break + b.write0(hbar) + } + } + } + + case Escape: + // start of escaped sequence + b.append(buf[n:i]) + b.updateWidth() + n = i + if b.flags&StripEscape != 0 { + n++ // strip Escape + } + b.startEscape(Escape) + + case '<', '&': + // possibly an html tag/entity + if b.flags&FilterHTML != 0 { + // begin of tag/entity + b.append(buf[n:i]) + b.updateWidth() + n = i + b.startEscape(ch) + } + } + + } else { + // inside escape + if ch == b.endChar { + // end of tag/entity + j := i + 1 + if ch == Escape && b.flags&StripEscape != 0 { + j = i // strip Escape + } + b.append(buf[n:j]) + n = i + 1 // ch consumed + b.endEscape() + } + } + } + + // append leftover text + b.append(buf[n:]) + n = len(buf) + return +} + +// NewWriter allocates and initializes a new tabwriter.Writer. +// The parameters are the same as for the Init function. +// +func NewWriter(output io.Writer, minwidth, tabwidth, padding int, padchar byte, flags uint) *Writer { + return new(Writer).Init(output, minwidth, tabwidth, padding, padchar, flags) +} diff --git a/src/text/tabwriter/tabwriter_test.go b/src/text/tabwriter/tabwriter_test.go new file mode 100644 index 000000000..9d3111e2c --- /dev/null +++ b/src/text/tabwriter/tabwriter_test.go @@ -0,0 +1,652 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package tabwriter_test + +import ( + "io" + "testing" + . "text/tabwriter" +) + +type buffer struct { + a []byte +} + +func (b *buffer) init(n int) { b.a = make([]byte, 0, n) } + +func (b *buffer) clear() { b.a = b.a[0:0] } + +func (b *buffer) Write(buf []byte) (written int, err error) { + n := len(b.a) + m := len(buf) + if n+m <= cap(b.a) { + b.a = b.a[0 : n+m] + for i := 0; i < m; i++ { + b.a[n+i] = buf[i] + } + } else { + panic("buffer.Write: buffer too small") + } + return len(buf), nil +} + +func (b *buffer) String() string { return string(b.a) } + +func write(t *testing.T, testname string, w *Writer, src string) { + written, err := io.WriteString(w, src) + if err != nil { + t.Errorf("--- test: %s\n--- src:\n%q\n--- write error: %v\n", testname, src, err) + } + if written != len(src) { + t.Errorf("--- test: %s\n--- src:\n%q\n--- written = %d, len(src) = %d\n", testname, src, written, len(src)) + } +} + +func verify(t *testing.T, testname string, w *Writer, b *buffer, src, expected string) { + err := w.Flush() + if err != nil { + t.Errorf("--- test: %s\n--- src:\n%q\n--- flush error: %v\n", testname, src, err) + } + + res := b.String() + if res != expected { + t.Errorf("--- test: %s\n--- src:\n%q\n--- found:\n%q\n--- expected:\n%q\n", testname, src, res, expected) + } +} + +func check(t *testing.T, testname string, minwidth, tabwidth, padding int, padchar byte, flags uint, src, expected string) { + var b buffer + b.init(1000) + + var w Writer + w.Init(&b, minwidth, tabwidth, padding, padchar, flags) + + // write all at once + title := testname + " (written all at once)" + b.clear() + write(t, title, &w, src) + verify(t, title, &w, &b, src, expected) + + // write byte-by-byte + title = testname + " (written byte-by-byte)" + b.clear() + for i := 0; i < len(src); i++ { + write(t, title, &w, src[i:i+1]) + } + verify(t, title, &w, &b, src, expected) + + // write using Fibonacci slice sizes + title = testname + " (written in fibonacci slices)" + b.clear() + for i, d := 0, 0; i < len(src); { + write(t, title, &w, src[i:i+d]) + i, d = i+d, d+1 + if i+d > len(src) { + d = len(src) - i + } + } + verify(t, title, &w, &b, src, expected) +} + +var tests = []struct { + testname string + minwidth, tabwidth, padding int + padchar byte + flags uint + src, expected string +}{ + { + "1a", + 8, 0, 1, '.', 0, + "", + "", + }, + + { + "1a debug", + 8, 0, 1, '.', Debug, + "", + "", + }, + + { + "1b esc stripped", + 8, 0, 1, '.', StripEscape, + "\xff\xff", + "", + }, + + { + "1b esc", + 8, 0, 1, '.', 0, + "\xff\xff", + "\xff\xff", + }, + + { + "1c esc stripped", + 8, 0, 1, '.', StripEscape, + "\xff\t\xff", + "\t", + }, + + { + "1c esc", + 8, 0, 1, '.', 0, + "\xff\t\xff", + "\xff\t\xff", + }, + + { + "1d esc stripped", + 8, 0, 1, '.', StripEscape, + "\xff\"foo\t\n\tbar\"\xff", + "\"foo\t\n\tbar\"", + }, + + { + "1d esc", + 8, 0, 1, '.', 0, + "\xff\"foo\t\n\tbar\"\xff", + "\xff\"foo\t\n\tbar\"\xff", + }, + + { + "1e esc stripped", + 8, 0, 1, '.', StripEscape, + "abc\xff\tdef", // unterminated escape + "abc\tdef", + }, + + { + "1e esc", + 8, 0, 1, '.', 0, + "abc\xff\tdef", // unterminated escape + "abc\xff\tdef", + }, + + { + "2", + 8, 0, 1, '.', 0, + "\n\n\n", + "\n\n\n", + }, + + { + "3", + 8, 0, 1, '.', 0, + "a\nb\nc", + "a\nb\nc", + }, + + { + "4a", + 8, 0, 1, '.', 0, + "\t", // '\t' terminates an empty cell on last line - nothing to print + "", + }, + + { + "4b", + 8, 0, 1, '.', AlignRight, + "\t", // '\t' terminates an empty cell on last line - nothing to print + "", + }, + + { + "5", + 8, 0, 1, '.', 0, + "*\t*", + "*.......*", + }, + + { + "5b", + 8, 0, 1, '.', 0, + "*\t*\n", + "*.......*\n", + }, + + { + "5c", + 8, 0, 1, '.', 0, + "*\t*\t", + "*.......*", + }, + + { + "5c debug", + 8, 0, 1, '.', Debug, + "*\t*\t", + "*.......|*", + }, + + { + "5d", + 8, 0, 1, '.', AlignRight, + "*\t*\t", + ".......**", + }, + + { + "6", + 8, 0, 1, '.', 0, + "\t\n", + "........\n", + }, + + { + "7a", + 8, 0, 1, '.', 0, + "a) foo", + "a) foo", + }, + + { + "7b", + 8, 0, 1, ' ', 0, + "b) foo\tbar", + "b) foo bar", + }, + + { + "7c", + 8, 0, 1, '.', 0, + "c) foo\tbar\t", + "c) foo..bar", + }, + + { + "7d", + 8, 0, 1, '.', 0, + "d) foo\tbar\n", + "d) foo..bar\n", + }, + + { + "7e", + 8, 0, 1, '.', 0, + "e) foo\tbar\t\n", + "e) foo..bar.....\n", + }, + + { + "7f", + 8, 0, 1, '.', FilterHTML, + "f) f<o\tbar\t\n", + "f) f<o..bar.....\n", + }, + + { + "7g", + 8, 0, 1, '.', FilterHTML, + "g) f<o\tbar\t non-terminated entity &", + "g) f<o..bar..... non-terminated entity &", + }, + + { + "7g debug", + 8, 0, 1, '.', FilterHTML | Debug, + "g) f<o\tbar\t non-terminated entity &", + "g) f<o..|bar.....| non-terminated entity &", + }, + + { + "8", + 8, 0, 1, '*', 0, + "Hello, world!\n", + "Hello, world!\n", + }, + + { + "9a", + 1, 0, 0, '.', 0, + "1\t2\t3\t4\n" + + "11\t222\t3333\t44444\n", + + "1.2..3...4\n" + + "11222333344444\n", + }, + + { + "9b", + 1, 0, 0, '.', FilterHTML, + "1\t2\t3\t4\n" + // \f inside HTML is ignored + "11\t222\t3333\t44444\n", + + "1.2..3...4\n" + + "11222333344444\n", + }, + + { + "9c", + 1, 0, 0, '.', 0, + "1\t2\t3\t4\f" + // \f causes a newline and flush + "11\t222\t3333\t44444\n", + + "1234\n" + + "11222333344444\n", + }, + + { + "9c debug", + 1, 0, 0, '.', Debug, + "1\t2\t3\t4\f" + // \f causes a newline and flush + "11\t222\t3333\t44444\n", + + "1|2|3|4\n" + + "---\n" + + "11|222|3333|44444\n", + }, + + { + "10a", + 5, 0, 0, '.', 0, + "1\t2\t3\t4\n", + "1....2....3....4\n", + }, + + { + "10b", + 5, 0, 0, '.', 0, + "1\t2\t3\t4\t\n", + "1....2....3....4....\n", + }, + + { + "11", + 8, 0, 1, '.', 0, + "本\tb\tc\n" + + "aa\t\u672c\u672c\u672c\tcccc\tddddd\n" + + "aaa\tbbbb\n", + + "本.......b.......c\n" + + "aa......本本本.....cccc....ddddd\n" + + "aaa.....bbbb\n", + }, + + { + "12a", + 8, 0, 1, ' ', AlignRight, + "a\tè\tc\t\n" + + "aa\tèèè\tcccc\tddddd\t\n" + + "aaa\tèèèè\t\n", + + " a è c\n" + + " aa èèè cccc ddddd\n" + + " aaa èèèè\n", + }, + + { + "12b", + 2, 0, 0, ' ', 0, + "a\tb\tc\n" + + "aa\tbbb\tcccc\n" + + "aaa\tbbbb\n", + + "a b c\n" + + "aa bbbcccc\n" + + "aaabbbb\n", + }, + + { + "12c", + 8, 0, 1, '_', 0, + "a\tb\tc\n" + + "aa\tbbb\tcccc\n" + + "aaa\tbbbb\n", + + "a_______b_______c\n" + + "aa______bbb_____cccc\n" + + "aaa_____bbbb\n", + }, + + { + "13a", + 4, 0, 1, '-', 0, + "4444\t日本語\t22\t1\t333\n" + + "999999999\t22\n" + + "7\t22\n" + + "\t\t\t88888888\n" + + "\n" + + "666666\t666666\t666666\t4444\n" + + "1\t1\t999999999\t0000000000\n", + + "4444------日本語-22--1---333\n" + + "999999999-22\n" + + "7---------22\n" + + "------------------88888888\n" + + "\n" + + "666666-666666-666666----4444\n" + + "1------1------999999999-0000000000\n", + }, + + { + "13b", + 4, 0, 3, '.', 0, + "4444\t333\t22\t1\t333\n" + + "999999999\t22\n" + + "7\t22\n" + + "\t\t\t88888888\n" + + "\n" + + "666666\t666666\t666666\t4444\n" + + "1\t1\t999999999\t0000000000\n", + + "4444........333...22...1...333\n" + + "999999999...22\n" + + "7...........22\n" + + "....................88888888\n" + + "\n" + + "666666...666666...666666......4444\n" + + "1........1........999999999...0000000000\n", + }, + + { + "13c", + 8, 8, 1, '\t', FilterHTML, + "4444\t333\t22\t1\t333\n" + + "999999999\t22\n" + + "7\t22\n" + + "\t\t\t88888888\n" + + "\n" + + "666666\t666666\t666666\t4444\n" + + "1\t1\t999999999\t0000000000\n", + + "4444\t\t333\t22\t1\t333\n" + + "999999999\t22\n" + + "7\t\t22\n" + + "\t\t\t\t88888888\n" + + "\n" + + "666666\t666666\t666666\t\t4444\n" + + "1\t1\t999999999\t0000000000\n", + }, + + { + "14", + 1, 0, 2, ' ', AlignRight, + ".0\t.3\t2.4\t-5.1\t\n" + + "23.0\t12345678.9\t2.4\t-989.4\t\n" + + "5.1\t12.0\t2.4\t-7.0\t\n" + + ".0\t0.0\t332.0\t8908.0\t\n" + + ".0\t-.3\t456.4\t22.1\t\n" + + ".0\t1.2\t44.4\t-13.3\t\t", + + " .0 .3 2.4 -5.1\n" + + " 23.0 12345678.9 2.4 -989.4\n" + + " 5.1 12.0 2.4 -7.0\n" + + " .0 0.0 332.0 8908.0\n" + + " .0 -.3 456.4 22.1\n" + + " .0 1.2 44.4 -13.3", + }, + + { + "14 debug", + 1, 0, 2, ' ', AlignRight | Debug, + ".0\t.3\t2.4\t-5.1\t\n" + + "23.0\t12345678.9\t2.4\t-989.4\t\n" + + "5.1\t12.0\t2.4\t-7.0\t\n" + + ".0\t0.0\t332.0\t8908.0\t\n" + + ".0\t-.3\t456.4\t22.1\t\n" + + ".0\t1.2\t44.4\t-13.3\t\t", + + " .0| .3| 2.4| -5.1|\n" + + " 23.0| 12345678.9| 2.4| -989.4|\n" + + " 5.1| 12.0| 2.4| -7.0|\n" + + " .0| 0.0| 332.0| 8908.0|\n" + + " .0| -.3| 456.4| 22.1|\n" + + " .0| 1.2| 44.4| -13.3|", + }, + + { + "15a", + 4, 0, 0, '.', 0, + "a\t\tb", + "a.......b", + }, + + { + "15b", + 4, 0, 0, '.', DiscardEmptyColumns, + "a\t\tb", // htabs - do not discard column + "a.......b", + }, + + { + "15c", + 4, 0, 0, '.', DiscardEmptyColumns, + "a\v\vb", + "a...b", + }, + + { + "15d", + 4, 0, 0, '.', AlignRight | DiscardEmptyColumns, + "a\v\vb", + "...ab", + }, + + { + "16a", + 100, 100, 0, '\t', 0, + "a\tb\t\td\n" + + "a\tb\t\td\te\n" + + "a\n" + + "a\tb\tc\td\n" + + "a\tb\tc\td\te\n", + + "a\tb\t\td\n" + + "a\tb\t\td\te\n" + + "a\n" + + "a\tb\tc\td\n" + + "a\tb\tc\td\te\n", + }, + + { + "16b", + 100, 100, 0, '\t', DiscardEmptyColumns, + "a\vb\v\vd\n" + + "a\vb\v\vd\ve\n" + + "a\n" + + "a\vb\vc\vd\n" + + "a\vb\vc\vd\ve\n", + + "a\tb\td\n" + + "a\tb\td\te\n" + + "a\n" + + "a\tb\tc\td\n" + + "a\tb\tc\td\te\n", + }, + + { + "16b debug", + 100, 100, 0, '\t', DiscardEmptyColumns | Debug, + "a\vb\v\vd\n" + + "a\vb\v\vd\ve\n" + + "a\n" + + "a\vb\vc\vd\n" + + "a\vb\vc\vd\ve\n", + + "a\t|b\t||d\n" + + "a\t|b\t||d\t|e\n" + + "a\n" + + "a\t|b\t|c\t|d\n" + + "a\t|b\t|c\t|d\t|e\n", + }, + + { + "16c", + 100, 100, 0, '\t', DiscardEmptyColumns, + "a\tb\t\td\n" + // hard tabs - do not discard column + "a\tb\t\td\te\n" + + "a\n" + + "a\tb\tc\td\n" + + "a\tb\tc\td\te\n", + + "a\tb\t\td\n" + + "a\tb\t\td\te\n" + + "a\n" + + "a\tb\tc\td\n" + + "a\tb\tc\td\te\n", + }, + + { + "16c debug", + 100, 100, 0, '\t', DiscardEmptyColumns | Debug, + "a\tb\t\td\n" + // hard tabs - do not discard column + "a\tb\t\td\te\n" + + "a\n" + + "a\tb\tc\td\n" + + "a\tb\tc\td\te\n", + + "a\t|b\t|\t|d\n" + + "a\t|b\t|\t|d\t|e\n" + + "a\n" + + "a\t|b\t|c\t|d\n" + + "a\t|b\t|c\t|d\t|e\n", + }, +} + +func Test(t *testing.T) { + for _, e := range tests { + check(t, e.testname, e.minwidth, e.tabwidth, e.padding, e.padchar, e.flags, e.src, e.expected) + } +} + +type panicWriter struct{} + +func (panicWriter) Write([]byte) (int, error) { + panic("cannot write") +} + +func wantPanicString(t *testing.T, want string) { + if e := recover(); e != nil { + got, ok := e.(string) + switch { + case !ok: + t.Errorf("got %v (%T), want panic string", e, e) + case got != want: + t.Errorf("wrong panic message: got %q, want %q", got, want) + } + } +} + +func TestPanicDuringFlush(t *testing.T) { + defer wantPanicString(t, "tabwriter: panic during Flush") + var p panicWriter + w := new(Writer) + w.Init(p, 0, 0, 5, ' ', 0) + io.WriteString(w, "a") + w.Flush() + t.Errorf("failed to panic during Flush") +} + +func TestPanicDuringWrite(t *testing.T) { + defer wantPanicString(t, "tabwriter: panic during Write") + var p panicWriter + w := new(Writer) + w.Init(p, 0, 0, 5, ' ', 0) + io.WriteString(w, "a\n\n") // the second \n triggers a call to w.Write and thus a panic + t.Errorf("failed to panic during Write") +} diff --git a/src/text/template/doc.go b/src/text/template/doc.go new file mode 100644 index 000000000..7c6efd59c --- /dev/null +++ b/src/text/template/doc.go @@ -0,0 +1,405 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* +Package template implements data-driven templates for generating textual output. + +To generate HTML output, see package html/template, which has the same interface +as this package but automatically secures HTML output against certain attacks. + +Templates are executed by applying them to a data structure. Annotations in the +template refer to elements of the data structure (typically a field of a struct +or a key in a map) to control execution and derive values to be displayed. +Execution of the template walks the structure and sets the cursor, represented +by a period '.' and called "dot", to the value at the current location in the +structure as execution proceeds. + +The input text for a template is UTF-8-encoded text in any format. +"Actions"--data evaluations or control structures--are delimited by +"{{" and "}}"; all text outside actions is copied to the output unchanged. +Actions may not span newlines, although comments can. + +Once parsed, a template may be executed safely in parallel. + +Here is a trivial example that prints "17 items are made of wool". + + type Inventory struct { + Material string + Count uint + } + sweaters := Inventory{"wool", 17} + tmpl, err := template.New("test").Parse("{{.Count}} items are made of {{.Material}}") + if err != nil { panic(err) } + err = tmpl.Execute(os.Stdout, sweaters) + if err != nil { panic(err) } + +More intricate examples appear below. + +Actions + +Here is the list of actions. "Arguments" and "pipelines" are evaluations of +data, defined in detail below. + +*/ +// {{/* a comment */}} +// A comment; discarded. May contain newlines. +// Comments do not nest and must start and end at the +// delimiters, as shown here. +/* + + {{pipeline}} + The default textual representation of the value of the pipeline + is copied to the output. + + {{if pipeline}} T1 {{end}} + If the value of the pipeline is empty, no output is generated; + otherwise, T1 is executed. The empty values are false, 0, any + nil pointer or interface value, and any array, slice, map, or + string of length zero. + Dot is unaffected. + + {{if pipeline}} T1 {{else}} T0 {{end}} + If the value of the pipeline is empty, T0 is executed; + otherwise, T1 is executed. Dot is unaffected. + + {{if pipeline}} T1 {{else if pipeline}} T0 {{end}} + To simplify the appearance of if-else chains, the else action + of an if may include another if directly; the effect is exactly + the same as writing + {{if pipeline}} T1 {{else}}{{if pipeline}} T0 {{end}}{{end}} + + {{range pipeline}} T1 {{end}} + The value of the pipeline must be an array, slice, map, or channel. + If the value of the pipeline has length zero, nothing is output; + otherwise, dot is set to the successive elements of the array, + slice, or map and T1 is executed. If the value is a map and the + keys are of basic type with a defined order ("comparable"), the + elements will be visited in sorted key order. + + {{range pipeline}} T1 {{else}} T0 {{end}} + The value of the pipeline must be an array, slice, map, or channel. + If the value of the pipeline has length zero, dot is unaffected and + T0 is executed; otherwise, dot is set to the successive elements + of the array, slice, or map and T1 is executed. + + {{template "name"}} + The template with the specified name is executed with nil data. + + {{template "name" pipeline}} + The template with the specified name is executed with dot set + to the value of the pipeline. + + {{with pipeline}} T1 {{end}} + If the value of the pipeline is empty, no output is generated; + otherwise, dot is set to the value of the pipeline and T1 is + executed. + + {{with pipeline}} T1 {{else}} T0 {{end}} + If the value of the pipeline is empty, dot is unaffected and T0 + is executed; otherwise, dot is set to the value of the pipeline + and T1 is executed. + +Arguments + +An argument is a simple value, denoted by one of the following. + + - A boolean, string, character, integer, floating-point, imaginary + or complex constant in Go syntax. These behave like Go's untyped + constants, although raw strings may not span newlines. + - The keyword nil, representing an untyped Go nil. + - The character '.' (period): + . + The result is the value of dot. + - A variable name, which is a (possibly empty) alphanumeric string + preceded by a dollar sign, such as + $piOver2 + or + $ + The result is the value of the variable. + Variables are described below. + - The name of a field of the data, which must be a struct, preceded + by a period, such as + .Field + The result is the value of the field. Field invocations may be + chained: + .Field1.Field2 + Fields can also be evaluated on variables, including chaining: + $x.Field1.Field2 + - The name of a key of the data, which must be a map, preceded + by a period, such as + .Key + The result is the map element value indexed by the key. + Key invocations may be chained and combined with fields to any + depth: + .Field1.Key1.Field2.Key2 + Although the key must be an alphanumeric identifier, unlike with + field names they do not need to start with an upper case letter. + Keys can also be evaluated on variables, including chaining: + $x.key1.key2 + - The name of a niladic method of the data, preceded by a period, + such as + .Method + The result is the value of invoking the method with dot as the + receiver, dot.Method(). Such a method must have one return value (of + any type) or two return values, the second of which is an error. + If it has two and the returned error is non-nil, execution terminates + and an error is returned to the caller as the value of Execute. + Method invocations may be chained and combined with fields and keys + to any depth: + .Field1.Key1.Method1.Field2.Key2.Method2 + Methods can also be evaluated on variables, including chaining: + $x.Method1.Field + - The name of a niladic function, such as + fun + The result is the value of invoking the function, fun(). The return + types and values behave as in methods. Functions and function + names are described below. + - A parenthesized instance of one the above, for grouping. The result + may be accessed by a field or map key invocation. + print (.F1 arg1) (.F2 arg2) + (.StructValuedMethod "arg").Field + +Arguments may evaluate to any type; if they are pointers the implementation +automatically indirects to the base type when required. +If an evaluation yields a function value, such as a function-valued +field of a struct, the function is not invoked automatically, but it +can be used as a truth value for an if action and the like. To invoke +it, use the call function, defined below. + +A pipeline is a possibly chained sequence of "commands". A command is a simple +value (argument) or a function or method call, possibly with multiple arguments: + + Argument + The result is the value of evaluating the argument. + .Method [Argument...] + The method can be alone or the last element of a chain but, + unlike methods in the middle of a chain, it can take arguments. + The result is the value of calling the method with the + arguments: + dot.Method(Argument1, etc.) + functionName [Argument...] + The result is the value of calling the function associated + with the name: + function(Argument1, etc.) + Functions and function names are described below. + +Pipelines + +A pipeline may be "chained" by separating a sequence of commands with pipeline +characters '|'. In a chained pipeline, the result of the each command is +passed as the last argument of the following command. The output of the final +command in the pipeline is the value of the pipeline. + +The output of a command will be either one value or two values, the second of +which has type error. If that second value is present and evaluates to +non-nil, execution terminates and the error is returned to the caller of +Execute. + +Variables + +A pipeline inside an action may initialize a variable to capture the result. +The initialization has syntax + + $variable := pipeline + +where $variable is the name of the variable. An action that declares a +variable produces no output. + +If a "range" action initializes a variable, the variable is set to the +successive elements of the iteration. Also, a "range" may declare two +variables, separated by a comma: + + range $index, $element := pipeline + +in which case $index and $element are set to the successive values of the +array/slice index or map key and element, respectively. Note that if there is +only one variable, it is assigned the element; this is opposite to the +convention in Go range clauses. + +A variable's scope extends to the "end" action of the control structure ("if", +"with", or "range") in which it is declared, or to the end of the template if +there is no such control structure. A template invocation does not inherit +variables from the point of its invocation. + +When execution begins, $ is set to the data argument passed to Execute, that is, +to the starting value of dot. + +Examples + +Here are some example one-line templates demonstrating pipelines and variables. +All produce the quoted word "output": + + {{"\"output\""}} + A string constant. + {{`"output"`}} + A raw string constant. + {{printf "%q" "output"}} + A function call. + {{"output" | printf "%q"}} + A function call whose final argument comes from the previous + command. + {{printf "%q" (print "out" "put")}} + A parenthesized argument. + {{"put" | printf "%s%s" "out" | printf "%q"}} + A more elaborate call. + {{"output" | printf "%s" | printf "%q"}} + A longer chain. + {{with "output"}}{{printf "%q" .}}{{end}} + A with action using dot. + {{with $x := "output" | printf "%q"}}{{$x}}{{end}} + A with action that creates and uses a variable. + {{with $x := "output"}}{{printf "%q" $x}}{{end}} + A with action that uses the variable in another action. + {{with $x := "output"}}{{$x | printf "%q"}}{{end}} + The same, but pipelined. + +Functions + +During execution functions are found in two function maps: first in the +template, then in the global function map. By default, no functions are defined +in the template but the Funcs method can be used to add them. + +Predefined global functions are named as follows. + + and + Returns the boolean AND of its arguments by returning the + first empty argument or the last argument, that is, + "and x y" behaves as "if x then y else x". All the + arguments are evaluated. + call + Returns the result of calling the first argument, which + must be a function, with the remaining arguments as parameters. + Thus "call .X.Y 1 2" is, in Go notation, dot.X.Y(1, 2) where + Y is a func-valued field, map entry, or the like. + The first argument must be the result of an evaluation + that yields a value of function type (as distinct from + a predefined function such as print). The function must + return either one or two result values, the second of which + is of type error. If the arguments don't match the function + or the returned error value is non-nil, execution stops. + html + Returns the escaped HTML equivalent of the textual + representation of its arguments. + index + Returns the result of indexing its first argument by the + following arguments. Thus "index x 1 2 3" is, in Go syntax, + x[1][2][3]. Each indexed item must be a map, slice, or array. + js + Returns the escaped JavaScript equivalent of the textual + representation of its arguments. + len + Returns the integer length of its argument. + not + Returns the boolean negation of its single argument. + or + Returns the boolean OR of its arguments by returning the + first non-empty argument or the last argument, that is, + "or x y" behaves as "if x then x else y". All the + arguments are evaluated. + print + An alias for fmt.Sprint + printf + An alias for fmt.Sprintf + println + An alias for fmt.Sprintln + urlquery + Returns the escaped value of the textual representation of + its arguments in a form suitable for embedding in a URL query. + +The boolean functions take any zero value to be false and a non-zero +value to be true. + +There is also a set of binary comparison operators defined as +functions: + + eq + Returns the boolean truth of arg1 == arg2 + ne + Returns the boolean truth of arg1 != arg2 + lt + Returns the boolean truth of arg1 < arg2 + le + Returns the boolean truth of arg1 <= arg2 + gt + Returns the boolean truth of arg1 > arg2 + ge + Returns the boolean truth of arg1 >= arg2 + +For simpler multi-way equality tests, eq (only) accepts two or more +arguments and compares the second and subsequent to the first, +returning in effect + + arg1==arg2 || arg1==arg3 || arg1==arg4 ... + +(Unlike with || in Go, however, eq is a function call and all the +arguments will be evaluated.) + +The comparison functions work on basic types only (or named basic +types, such as "type Celsius float32"). They implement the Go rules +for comparison of values, except that size and exact type are +ignored, so any integer value may be compared with any other integer +value, any unsigned integer value may be compared with any other +unsigned integer value, and so on. However, as usual, one may not +compare an int with a float32 and so on. + +Associated templates + +Each template is named by a string specified when it is created. Also, each +template is associated with zero or more other templates that it may invoke by +name; such associations are transitive and form a name space of templates. + +A template may use a template invocation to instantiate another associated +template; see the explanation of the "template" action above. The name must be +that of a template associated with the template that contains the invocation. + +Nested template definitions + +When parsing a template, another template may be defined and associated with the +template being parsed. Template definitions must appear at the top level of the +template, much like global variables in a Go program. + +The syntax of such definitions is to surround each template declaration with a +"define" and "end" action. + +The define action names the template being created by providing a string +constant. Here is a simple example: + + `{{define "T1"}}ONE{{end}} + {{define "T2"}}TWO{{end}} + {{define "T3"}}{{template "T1"}} {{template "T2"}}{{end}} + {{template "T3"}}` + +This defines two templates, T1 and T2, and a third T3 that invokes the other two +when it is executed. Finally it invokes T3. If executed this template will +produce the text + + ONE TWO + +By construction, a template may reside in only one association. If it's +necessary to have a template addressable from multiple associations, the +template definition must be parsed multiple times to create distinct *Template +values, or must be copied with the Clone or AddParseTree method. + +Parse may be called multiple times to assemble the various associated templates; +see the ParseFiles and ParseGlob functions and methods for simple ways to parse +related templates stored in files. + +A template may be executed directly or through ExecuteTemplate, which executes +an associated template identified by name. To invoke our example above, we +might write, + + err := tmpl.Execute(os.Stdout, "no data needed") + if err != nil { + log.Fatalf("execution failed: %s", err) + } + +or to invoke a particular template explicitly by name, + + err := tmpl.ExecuteTemplate(os.Stdout, "T2", "no data needed") + if err != nil { + log.Fatalf("execution failed: %s", err) + } + +*/ +package template diff --git a/src/text/template/example_test.go b/src/text/template/example_test.go new file mode 100644 index 000000000..de1d51851 --- /dev/null +++ b/src/text/template/example_test.go @@ -0,0 +1,71 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package template_test + +import ( + "log" + "os" + "text/template" +) + +func ExampleTemplate() { + // Define a template. + const letter = ` +Dear {{.Name}}, +{{if .Attended}} +It was a pleasure to see you at the wedding.{{else}} +It is a shame you couldn't make it to the wedding.{{end}} +{{with .Gift}}Thank you for the lovely {{.}}. +{{end}} +Best wishes, +Josie +` + + // Prepare some data to insert into the template. + type Recipient struct { + Name, Gift string + Attended bool + } + var recipients = []Recipient{ + {"Aunt Mildred", "bone china tea set", true}, + {"Uncle John", "moleskin pants", false}, + {"Cousin Rodney", "", false}, + } + + // Create a new template and parse the letter into it. + t := template.Must(template.New("letter").Parse(letter)) + + // Execute the template for each recipient. + for _, r := range recipients { + err := t.Execute(os.Stdout, r) + if err != nil { + log.Println("executing template:", err) + } + } + + // Output: + // Dear Aunt Mildred, + // + // It was a pleasure to see you at the wedding. + // Thank you for the lovely bone china tea set. + // + // Best wishes, + // Josie + // + // Dear Uncle John, + // + // It is a shame you couldn't make it to the wedding. + // Thank you for the lovely moleskin pants. + // + // Best wishes, + // Josie + // + // Dear Cousin Rodney, + // + // It is a shame you couldn't make it to the wedding. + // + // Best wishes, + // Josie +} diff --git a/src/text/template/examplefiles_test.go b/src/text/template/examplefiles_test.go new file mode 100644 index 000000000..a15c7a62a --- /dev/null +++ b/src/text/template/examplefiles_test.go @@ -0,0 +1,182 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package template_test + +import ( + "io" + "io/ioutil" + "log" + "os" + "path/filepath" + "text/template" +) + +// templateFile defines the contents of a template to be stored in a file, for testing. +type templateFile struct { + name string + contents string +} + +func createTestDir(files []templateFile) string { + dir, err := ioutil.TempDir("", "template") + if err != nil { + log.Fatal(err) + } + for _, file := range files { + f, err := os.Create(filepath.Join(dir, file.name)) + if err != nil { + log.Fatal(err) + } + defer f.Close() + _, err = io.WriteString(f, file.contents) + if err != nil { + log.Fatal(err) + } + } + return dir +} + +// Here we demonstrate loading a set of templates from a directory. +func ExampleTemplate_glob() { + // Here we create a temporary directory and populate it with our sample + // template definition files; usually the template files would already + // exist in some location known to the program. + dir := createTestDir([]templateFile{ + // T0.tmpl is a plain template file that just invokes T1. + {"T0.tmpl", `T0 invokes T1: ({{template "T1"}})`}, + // T1.tmpl defines a template, T1 that invokes T2. + {"T1.tmpl", `{{define "T1"}}T1 invokes T2: ({{template "T2"}}){{end}}`}, + // T2.tmpl defines a template T2. + {"T2.tmpl", `{{define "T2"}}This is T2{{end}}`}, + }) + // Clean up after the test; another quirk of running as an example. + defer os.RemoveAll(dir) + + // pattern is the glob pattern used to find all the template files. + pattern := filepath.Join(dir, "*.tmpl") + + // Here starts the example proper. + // T0.tmpl is the first name matched, so it becomes the starting template, + // the value returned by ParseGlob. + tmpl := template.Must(template.ParseGlob(pattern)) + + err := tmpl.Execute(os.Stdout, nil) + if err != nil { + log.Fatalf("template execution: %s", err) + } + // Output: + // T0 invokes T1: (T1 invokes T2: (This is T2)) +} + +// This example demonstrates one way to share some templates +// and use them in different contexts. In this variant we add multiple driver +// templates by hand to an existing bundle of templates. +func ExampleTemplate_helpers() { + // Here we create a temporary directory and populate it with our sample + // template definition files; usually the template files would already + // exist in some location known to the program. + dir := createTestDir([]templateFile{ + // T1.tmpl defines a template, T1 that invokes T2. + {"T1.tmpl", `{{define "T1"}}T1 invokes T2: ({{template "T2"}}){{end}}`}, + // T2.tmpl defines a template T2. + {"T2.tmpl", `{{define "T2"}}This is T2{{end}}`}, + }) + // Clean up after the test; another quirk of running as an example. + defer os.RemoveAll(dir) + + // pattern is the glob pattern used to find all the template files. + pattern := filepath.Join(dir, "*.tmpl") + + // Here starts the example proper. + // Load the helpers. + templates := template.Must(template.ParseGlob(pattern)) + // Add one driver template to the bunch; we do this with an explicit template definition. + _, err := templates.Parse("{{define `driver1`}}Driver 1 calls T1: ({{template `T1`}})\n{{end}}") + if err != nil { + log.Fatal("parsing driver1: ", err) + } + // Add another driver template. + _, err = templates.Parse("{{define `driver2`}}Driver 2 calls T2: ({{template `T2`}})\n{{end}}") + if err != nil { + log.Fatal("parsing driver2: ", err) + } + // We load all the templates before execution. This package does not require + // that behavior but html/template's escaping does, so it's a good habit. + err = templates.ExecuteTemplate(os.Stdout, "driver1", nil) + if err != nil { + log.Fatalf("driver1 execution: %s", err) + } + err = templates.ExecuteTemplate(os.Stdout, "driver2", nil) + if err != nil { + log.Fatalf("driver2 execution: %s", err) + } + // Output: + // Driver 1 calls T1: (T1 invokes T2: (This is T2)) + // Driver 2 calls T2: (This is T2) +} + +// This example demonstrates how to use one group of driver +// templates with distinct sets of helper templates. +func ExampleTemplate_share() { + // Here we create a temporary directory and populate it with our sample + // template definition files; usually the template files would already + // exist in some location known to the program. + dir := createTestDir([]templateFile{ + // T0.tmpl is a plain template file that just invokes T1. + {"T0.tmpl", "T0 ({{.}} version) invokes T1: ({{template `T1`}})\n"}, + // T1.tmpl defines a template, T1 that invokes T2. Note T2 is not defined + {"T1.tmpl", `{{define "T1"}}T1 invokes T2: ({{template "T2"}}){{end}}`}, + }) + // Clean up after the test; another quirk of running as an example. + defer os.RemoveAll(dir) + + // pattern is the glob pattern used to find all the template files. + pattern := filepath.Join(dir, "*.tmpl") + + // Here starts the example proper. + // Load the drivers. + drivers := template.Must(template.ParseGlob(pattern)) + + // We must define an implementation of the T2 template. First we clone + // the drivers, then add a definition of T2 to the template name space. + + // 1. Clone the helper set to create a new name space from which to run them. + first, err := drivers.Clone() + if err != nil { + log.Fatal("cloning helpers: ", err) + } + // 2. Define T2, version A, and parse it. + _, err = first.Parse("{{define `T2`}}T2, version A{{end}}") + if err != nil { + log.Fatal("parsing T2: ", err) + } + + // Now repeat the whole thing, using a different version of T2. + // 1. Clone the drivers. + second, err := drivers.Clone() + if err != nil { + log.Fatal("cloning drivers: ", err) + } + // 2. Define T2, version B, and parse it. + _, err = second.Parse("{{define `T2`}}T2, version B{{end}}") + if err != nil { + log.Fatal("parsing T2: ", err) + } + + // Execute the templates in the reverse order to verify the + // first is unaffected by the second. + err = second.ExecuteTemplate(os.Stdout, "T0.tmpl", "second") + if err != nil { + log.Fatalf("second execution: %s", err) + } + err = first.ExecuteTemplate(os.Stdout, "T0.tmpl", "first") + if err != nil { + log.Fatalf("first: execution: %s", err) + } + + // Output: + // T0 (second version) invokes T1: (T1 invokes T2: (T2, version B)) + // T0 (first version) invokes T1: (T1 invokes T2: (T2, version A)) +} diff --git a/src/text/template/examplefunc_test.go b/src/text/template/examplefunc_test.go new file mode 100644 index 000000000..080b5e3a0 --- /dev/null +++ b/src/text/template/examplefunc_test.go @@ -0,0 +1,54 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package template_test + +import ( + "log" + "os" + "strings" + "text/template" +) + +// This example demonstrates a custom function to process template text. +// It installs the strings.Title function and uses it to +// Make Title Text Look Good In Our Template's Output. +func ExampleTemplate_func() { + // First we create a FuncMap with which to register the function. + funcMap := template.FuncMap{ + // The name "title" is what the function will be called in the template text. + "title": strings.Title, + } + + // A simple template definition to test our function. + // We print the input text several ways: + // - the original + // - title-cased + // - title-cased and then printed with %q + // - printed with %q and then title-cased. + const templateText = ` +Input: {{printf "%q" .}} +Output 0: {{title .}} +Output 1: {{title . | printf "%q"}} +Output 2: {{printf "%q" . | title}} +` + + // Create a template, add the function map, and parse the text. + tmpl, err := template.New("titleTest").Funcs(funcMap).Parse(templateText) + if err != nil { + log.Fatalf("parsing: %s", err) + } + + // Run the template to verify the output. + err = tmpl.Execute(os.Stdout, "the go programming language") + if err != nil { + log.Fatalf("execution: %s", err) + } + + // Output: + // Input: "the go programming language" + // Output 0: The Go Programming Language + // Output 1: "The Go Programming Language" + // Output 2: "The Go Programming Language" +} diff --git a/src/text/template/exec.go b/src/text/template/exec.go new file mode 100644 index 000000000..8e155d478 --- /dev/null +++ b/src/text/template/exec.go @@ -0,0 +1,842 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package template + +import ( + "bytes" + "fmt" + "io" + "reflect" + "runtime" + "sort" + "strings" + "text/template/parse" +) + +// state represents the state of an execution. It's not part of the +// template so that multiple executions of the same template +// can execute in parallel. +type state struct { + tmpl *Template + wr io.Writer + node parse.Node // current node, for errors + vars []variable // push-down stack of variable values. +} + +// variable holds the dynamic value of a variable such as $, $x etc. +type variable struct { + name string + value reflect.Value +} + +// push pushes a new variable on the stack. +func (s *state) push(name string, value reflect.Value) { + s.vars = append(s.vars, variable{name, value}) +} + +// mark returns the length of the variable stack. +func (s *state) mark() int { + return len(s.vars) +} + +// pop pops the variable stack up to the mark. +func (s *state) pop(mark int) { + s.vars = s.vars[0:mark] +} + +// setVar overwrites the top-nth variable on the stack. Used by range iterations. +func (s *state) setVar(n int, value reflect.Value) { + s.vars[len(s.vars)-n].value = value +} + +// varValue returns the value of the named variable. +func (s *state) varValue(name string) reflect.Value { + for i := s.mark() - 1; i >= 0; i-- { + if s.vars[i].name == name { + return s.vars[i].value + } + } + s.errorf("undefined variable: %s", name) + return zero +} + +var zero reflect.Value + +// at marks the state to be on node n, for error reporting. +func (s *state) at(node parse.Node) { + s.node = node +} + +// doublePercent returns the string with %'s replaced by %%, if necessary, +// so it can be used safely inside a Printf format string. +func doublePercent(str string) string { + if strings.Contains(str, "%") { + str = strings.Replace(str, "%", "%%", -1) + } + return str +} + +// errorf formats the error and terminates processing. +func (s *state) errorf(format string, args ...interface{}) { + name := doublePercent(s.tmpl.Name()) + if s.node == nil { + format = fmt.Sprintf("template: %s: %s", name, format) + } else { + location, context := s.tmpl.ErrorContext(s.node) + format = fmt.Sprintf("template: %s: executing %q at <%s>: %s", location, name, doublePercent(context), format) + } + panic(fmt.Errorf(format, args...)) +} + +// errRecover is the handler that turns panics into returns from the top +// level of Parse. +func errRecover(errp *error) { + e := recover() + if e != nil { + switch err := e.(type) { + case runtime.Error: + panic(e) + case error: + *errp = err + default: + panic(e) + } + } +} + +// ExecuteTemplate applies the template associated with t that has the given name +// to the specified data object and writes the output to wr. +// If an error occurs executing the template or writing its output, +// execution stops, but partial results may already have been written to +// the output writer. +// A template may be executed safely in parallel. +func (t *Template) ExecuteTemplate(wr io.Writer, name string, data interface{}) error { + tmpl := t.tmpl[name] + if tmpl == nil { + return fmt.Errorf("template: no template %q associated with template %q", name, t.name) + } + return tmpl.Execute(wr, data) +} + +// Execute applies a parsed template to the specified data object, +// and writes the output to wr. +// If an error occurs executing the template or writing its output, +// execution stops, but partial results may already have been written to +// the output writer. +// A template may be executed safely in parallel. +func (t *Template) Execute(wr io.Writer, data interface{}) (err error) { + defer errRecover(&err) + value := reflect.ValueOf(data) + state := &state{ + tmpl: t, + wr: wr, + vars: []variable{{"$", value}}, + } + t.init() + if t.Tree == nil || t.Root == nil { + var b bytes.Buffer + for name, tmpl := range t.tmpl { + if tmpl.Tree == nil || tmpl.Root == nil { + continue + } + if b.Len() > 0 { + b.WriteString(", ") + } + fmt.Fprintf(&b, "%q", name) + } + var s string + if b.Len() > 0 { + s = "; defined templates are: " + b.String() + } + state.errorf("%q is an incomplete or empty template%s", t.Name(), s) + } + state.walk(value, t.Root) + return +} + +// Walk functions step through the major pieces of the template structure, +// generating output as they go. +func (s *state) walk(dot reflect.Value, node parse.Node) { + s.at(node) + switch node := node.(type) { + case *parse.ActionNode: + // Do not pop variables so they persist until next end. + // Also, if the action declares variables, don't print the result. + val := s.evalPipeline(dot, node.Pipe) + if len(node.Pipe.Decl) == 0 { + s.printValue(node, val) + } + case *parse.IfNode: + s.walkIfOrWith(parse.NodeIf, dot, node.Pipe, node.List, node.ElseList) + case *parse.ListNode: + for _, node := range node.Nodes { + s.walk(dot, node) + } + case *parse.RangeNode: + s.walkRange(dot, node) + case *parse.TemplateNode: + s.walkTemplate(dot, node) + case *parse.TextNode: + if _, err := s.wr.Write(node.Text); err != nil { + s.errorf("%s", err) + } + case *parse.WithNode: + s.walkIfOrWith(parse.NodeWith, dot, node.Pipe, node.List, node.ElseList) + default: + s.errorf("unknown node: %s", node) + } +} + +// walkIfOrWith walks an 'if' or 'with' node. The two control structures +// are identical in behavior except that 'with' sets dot. +func (s *state) walkIfOrWith(typ parse.NodeType, dot reflect.Value, pipe *parse.PipeNode, list, elseList *parse.ListNode) { + defer s.pop(s.mark()) + val := s.evalPipeline(dot, pipe) + truth, ok := isTrue(val) + if !ok { + s.errorf("if/with can't use %v", val) + } + if truth { + if typ == parse.NodeWith { + s.walk(val, list) + } else { + s.walk(dot, list) + } + } else if elseList != nil { + s.walk(dot, elseList) + } +} + +// isTrue reports whether the value is 'true', in the sense of not the zero of its type, +// and whether the value has a meaningful truth value. +func isTrue(val reflect.Value) (truth, ok bool) { + if !val.IsValid() { + // Something like var x interface{}, never set. It's a form of nil. + return false, true + } + switch val.Kind() { + case reflect.Array, reflect.Map, reflect.Slice, reflect.String: + truth = val.Len() > 0 + case reflect.Bool: + truth = val.Bool() + case reflect.Complex64, reflect.Complex128: + truth = val.Complex() != 0 + case reflect.Chan, reflect.Func, reflect.Ptr, reflect.Interface: + truth = !val.IsNil() + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + truth = val.Int() != 0 + case reflect.Float32, reflect.Float64: + truth = val.Float() != 0 + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + truth = val.Uint() != 0 + case reflect.Struct: + truth = true // Struct values are always true. + default: + return + } + return truth, true +} + +func (s *state) walkRange(dot reflect.Value, r *parse.RangeNode) { + s.at(r) + defer s.pop(s.mark()) + val, _ := indirect(s.evalPipeline(dot, r.Pipe)) + // mark top of stack before any variables in the body are pushed. + mark := s.mark() + oneIteration := func(index, elem reflect.Value) { + // Set top var (lexically the second if there are two) to the element. + if len(r.Pipe.Decl) > 0 { + s.setVar(1, elem) + } + // Set next var (lexically the first if there are two) to the index. + if len(r.Pipe.Decl) > 1 { + s.setVar(2, index) + } + s.walk(elem, r.List) + s.pop(mark) + } + switch val.Kind() { + case reflect.Array, reflect.Slice: + if val.Len() == 0 { + break + } + for i := 0; i < val.Len(); i++ { + oneIteration(reflect.ValueOf(i), val.Index(i)) + } + return + case reflect.Map: + if val.Len() == 0 { + break + } + for _, key := range sortKeys(val.MapKeys()) { + oneIteration(key, val.MapIndex(key)) + } + return + case reflect.Chan: + if val.IsNil() { + break + } + i := 0 + for ; ; i++ { + elem, ok := val.Recv() + if !ok { + break + } + oneIteration(reflect.ValueOf(i), elem) + } + if i == 0 { + break + } + return + case reflect.Invalid: + break // An invalid value is likely a nil map, etc. and acts like an empty map. + default: + s.errorf("range can't iterate over %v", val) + } + if r.ElseList != nil { + s.walk(dot, r.ElseList) + } +} + +func (s *state) walkTemplate(dot reflect.Value, t *parse.TemplateNode) { + s.at(t) + tmpl := s.tmpl.tmpl[t.Name] + if tmpl == nil { + s.errorf("template %q not defined", t.Name) + } + // Variables declared by the pipeline persist. + dot = s.evalPipeline(dot, t.Pipe) + newState := *s + newState.tmpl = tmpl + // No dynamic scoping: template invocations inherit no variables. + newState.vars = []variable{{"$", dot}} + newState.walk(dot, tmpl.Root) +} + +// Eval functions evaluate pipelines, commands, and their elements and extract +// values from the data structure by examining fields, calling methods, and so on. +// The printing of those values happens only through walk functions. + +// evalPipeline returns the value acquired by evaluating a pipeline. If the +// pipeline has a variable declaration, the variable will be pushed on the +// stack. Callers should therefore pop the stack after they are finished +// executing commands depending on the pipeline value. +func (s *state) evalPipeline(dot reflect.Value, pipe *parse.PipeNode) (value reflect.Value) { + if pipe == nil { + return + } + s.at(pipe) + for _, cmd := range pipe.Cmds { + value = s.evalCommand(dot, cmd, value) // previous value is this one's final arg. + // If the object has type interface{}, dig down one level to the thing inside. + if value.Kind() == reflect.Interface && value.Type().NumMethod() == 0 { + value = reflect.ValueOf(value.Interface()) // lovely! + } + } + for _, variable := range pipe.Decl { + s.push(variable.Ident[0], value) + } + return value +} + +func (s *state) notAFunction(args []parse.Node, final reflect.Value) { + if len(args) > 1 || final.IsValid() { + s.errorf("can't give argument to non-function %s", args[0]) + } +} + +func (s *state) evalCommand(dot reflect.Value, cmd *parse.CommandNode, final reflect.Value) reflect.Value { + firstWord := cmd.Args[0] + switch n := firstWord.(type) { + case *parse.FieldNode: + return s.evalFieldNode(dot, n, cmd.Args, final) + case *parse.ChainNode: + return s.evalChainNode(dot, n, cmd.Args, final) + case *parse.IdentifierNode: + // Must be a function. + return s.evalFunction(dot, n, cmd, cmd.Args, final) + case *parse.PipeNode: + // Parenthesized pipeline. The arguments are all inside the pipeline; final is ignored. + return s.evalPipeline(dot, n) + case *parse.VariableNode: + return s.evalVariableNode(dot, n, cmd.Args, final) + } + s.at(firstWord) + s.notAFunction(cmd.Args, final) + switch word := firstWord.(type) { + case *parse.BoolNode: + return reflect.ValueOf(word.True) + case *parse.DotNode: + return dot + case *parse.NilNode: + s.errorf("nil is not a command") + case *parse.NumberNode: + return s.idealConstant(word) + case *parse.StringNode: + return reflect.ValueOf(word.Text) + } + s.errorf("can't evaluate command %q", firstWord) + panic("not reached") +} + +// idealConstant is called to return the value of a number in a context where +// we don't know the type. In that case, the syntax of the number tells us +// its type, and we use Go rules to resolve. Note there is no such thing as +// a uint ideal constant in this situation - the value must be of int type. +func (s *state) idealConstant(constant *parse.NumberNode) reflect.Value { + // These are ideal constants but we don't know the type + // and we have no context. (If it was a method argument, + // we'd know what we need.) The syntax guides us to some extent. + s.at(constant) + switch { + case constant.IsComplex: + return reflect.ValueOf(constant.Complex128) // incontrovertible. + case constant.IsFloat && !isHexConstant(constant.Text) && strings.IndexAny(constant.Text, ".eE") >= 0: + return reflect.ValueOf(constant.Float64) + case constant.IsInt: + n := int(constant.Int64) + if int64(n) != constant.Int64 { + s.errorf("%s overflows int", constant.Text) + } + return reflect.ValueOf(n) + case constant.IsUint: + s.errorf("%s overflows int", constant.Text) + } + return zero +} + +func isHexConstant(s string) bool { + return len(s) > 2 && s[0] == '0' && (s[1] == 'x' || s[1] == 'X') +} + +func (s *state) evalFieldNode(dot reflect.Value, field *parse.FieldNode, args []parse.Node, final reflect.Value) reflect.Value { + s.at(field) + return s.evalFieldChain(dot, dot, field, field.Ident, args, final) +} + +func (s *state) evalChainNode(dot reflect.Value, chain *parse.ChainNode, args []parse.Node, final reflect.Value) reflect.Value { + s.at(chain) + // (pipe).Field1.Field2 has pipe as .Node, fields as .Field. Eval the pipeline, then the fields. + pipe := s.evalArg(dot, nil, chain.Node) + if len(chain.Field) == 0 { + s.errorf("internal error: no fields in evalChainNode") + } + return s.evalFieldChain(dot, pipe, chain, chain.Field, args, final) +} + +func (s *state) evalVariableNode(dot reflect.Value, variable *parse.VariableNode, args []parse.Node, final reflect.Value) reflect.Value { + // $x.Field has $x as the first ident, Field as the second. Eval the var, then the fields. + s.at(variable) + value := s.varValue(variable.Ident[0]) + if len(variable.Ident) == 1 { + s.notAFunction(args, final) + return value + } + return s.evalFieldChain(dot, value, variable, variable.Ident[1:], args, final) +} + +// evalFieldChain evaluates .X.Y.Z possibly followed by arguments. +// dot is the environment in which to evaluate arguments, while +// receiver is the value being walked along the chain. +func (s *state) evalFieldChain(dot, receiver reflect.Value, node parse.Node, ident []string, args []parse.Node, final reflect.Value) reflect.Value { + n := len(ident) + for i := 0; i < n-1; i++ { + receiver = s.evalField(dot, ident[i], node, nil, zero, receiver) + } + // Now if it's a method, it gets the arguments. + return s.evalField(dot, ident[n-1], node, args, final, receiver) +} + +func (s *state) evalFunction(dot reflect.Value, node *parse.IdentifierNode, cmd parse.Node, args []parse.Node, final reflect.Value) reflect.Value { + s.at(node) + name := node.Ident + function, ok := findFunction(name, s.tmpl) + if !ok { + s.errorf("%q is not a defined function", name) + } + return s.evalCall(dot, function, cmd, name, args, final) +} + +// evalField evaluates an expression like (.Field) or (.Field arg1 arg2). +// The 'final' argument represents the return value from the preceding +// value of the pipeline, if any. +func (s *state) evalField(dot reflect.Value, fieldName string, node parse.Node, args []parse.Node, final, receiver reflect.Value) reflect.Value { + if !receiver.IsValid() { + return zero + } + typ := receiver.Type() + receiver, _ = indirect(receiver) + // Unless it's an interface, need to get to a value of type *T to guarantee + // we see all methods of T and *T. + ptr := receiver + if ptr.Kind() != reflect.Interface && ptr.CanAddr() { + ptr = ptr.Addr() + } + if method := ptr.MethodByName(fieldName); method.IsValid() { + return s.evalCall(dot, method, node, fieldName, args, final) + } + hasArgs := len(args) > 1 || final.IsValid() + // It's not a method; must be a field of a struct or an element of a map. The receiver must not be nil. + receiver, isNil := indirect(receiver) + if isNil { + s.errorf("nil pointer evaluating %s.%s", typ, fieldName) + } + switch receiver.Kind() { + case reflect.Struct: + tField, ok := receiver.Type().FieldByName(fieldName) + if ok { + field := receiver.FieldByIndex(tField.Index) + if tField.PkgPath != "" { // field is unexported + s.errorf("%s is an unexported field of struct type %s", fieldName, typ) + } + // If it's a function, we must call it. + if hasArgs { + s.errorf("%s has arguments but cannot be invoked as function", fieldName) + } + return field + } + s.errorf("%s is not a field of struct type %s", fieldName, typ) + case reflect.Map: + // If it's a map, attempt to use the field name as a key. + nameVal := reflect.ValueOf(fieldName) + if nameVal.Type().AssignableTo(receiver.Type().Key()) { + if hasArgs { + s.errorf("%s is not a method but has arguments", fieldName) + } + return receiver.MapIndex(nameVal) + } + } + s.errorf("can't evaluate field %s in type %s", fieldName, typ) + panic("not reached") +} + +var ( + errorType = reflect.TypeOf((*error)(nil)).Elem() + fmtStringerType = reflect.TypeOf((*fmt.Stringer)(nil)).Elem() +) + +// evalCall executes a function or method call. If it's a method, fun already has the receiver bound, so +// it looks just like a function call. The arg list, if non-nil, includes (in the manner of the shell), arg[0] +// as the function itself. +func (s *state) evalCall(dot, fun reflect.Value, node parse.Node, name string, args []parse.Node, final reflect.Value) reflect.Value { + if args != nil { + args = args[1:] // Zeroth arg is function name/node; not passed to function. + } + typ := fun.Type() + numIn := len(args) + if final.IsValid() { + numIn++ + } + numFixed := len(args) + if typ.IsVariadic() { + numFixed = typ.NumIn() - 1 // last arg is the variadic one. + if numIn < numFixed { + s.errorf("wrong number of args for %s: want at least %d got %d", name, typ.NumIn()-1, len(args)) + } + } else if numIn < typ.NumIn()-1 || !typ.IsVariadic() && numIn != typ.NumIn() { + s.errorf("wrong number of args for %s: want %d got %d", name, typ.NumIn(), len(args)) + } + if !goodFunc(typ) { + // TODO: This could still be a confusing error; maybe goodFunc should provide info. + s.errorf("can't call method/function %q with %d results", name, typ.NumOut()) + } + // Build the arg list. + argv := make([]reflect.Value, numIn) + // Args must be evaluated. Fixed args first. + i := 0 + for ; i < numFixed; i++ { + argv[i] = s.evalArg(dot, typ.In(i), args[i]) + } + // Now the ... args. + if typ.IsVariadic() { + argType := typ.In(typ.NumIn() - 1).Elem() // Argument is a slice. + for ; i < len(args); i++ { + argv[i] = s.evalArg(dot, argType, args[i]) + } + } + // Add final value if necessary. + if final.IsValid() { + t := typ.In(typ.NumIn() - 1) + if typ.IsVariadic() { + t = t.Elem() + } + argv[i] = s.validateType(final, t) + } + result := fun.Call(argv) + // If we have an error that is not nil, stop execution and return that error to the caller. + if len(result) == 2 && !result[1].IsNil() { + s.at(node) + s.errorf("error calling %s: %s", name, result[1].Interface().(error)) + } + return result[0] +} + +// canBeNil reports whether an untyped nil can be assigned to the type. See reflect.Zero. +func canBeNil(typ reflect.Type) bool { + switch typ.Kind() { + case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice: + return true + } + return false +} + +// validateType guarantees that the value is valid and assignable to the type. +func (s *state) validateType(value reflect.Value, typ reflect.Type) reflect.Value { + if !value.IsValid() { + if typ == nil || canBeNil(typ) { + // An untyped nil interface{}. Accept as a proper nil value. + return reflect.Zero(typ) + } + s.errorf("invalid value; expected %s", typ) + } + if typ != nil && !value.Type().AssignableTo(typ) { + if value.Kind() == reflect.Interface && !value.IsNil() { + value = value.Elem() + if value.Type().AssignableTo(typ) { + return value + } + // fallthrough + } + // Does one dereference or indirection work? We could do more, as we + // do with method receivers, but that gets messy and method receivers + // are much more constrained, so it makes more sense there than here. + // Besides, one is almost always all you need. + switch { + case value.Kind() == reflect.Ptr && value.Type().Elem().AssignableTo(typ): + value = value.Elem() + if !value.IsValid() { + s.errorf("dereference of nil pointer of type %s", typ) + } + case reflect.PtrTo(value.Type()).AssignableTo(typ) && value.CanAddr(): + value = value.Addr() + default: + s.errorf("wrong type for value; expected %s; got %s", typ, value.Type()) + } + } + return value +} + +func (s *state) evalArg(dot reflect.Value, typ reflect.Type, n parse.Node) reflect.Value { + s.at(n) + switch arg := n.(type) { + case *parse.DotNode: + return s.validateType(dot, typ) + case *parse.NilNode: + if canBeNil(typ) { + return reflect.Zero(typ) + } + s.errorf("cannot assign nil to %s", typ) + case *parse.FieldNode: + return s.validateType(s.evalFieldNode(dot, arg, []parse.Node{n}, zero), typ) + case *parse.VariableNode: + return s.validateType(s.evalVariableNode(dot, arg, nil, zero), typ) + case *parse.PipeNode: + return s.validateType(s.evalPipeline(dot, arg), typ) + case *parse.IdentifierNode: + return s.evalFunction(dot, arg, arg, nil, zero) + } + switch typ.Kind() { + case reflect.Bool: + return s.evalBool(typ, n) + case reflect.Complex64, reflect.Complex128: + return s.evalComplex(typ, n) + case reflect.Float32, reflect.Float64: + return s.evalFloat(typ, n) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + return s.evalInteger(typ, n) + case reflect.Interface: + if typ.NumMethod() == 0 { + return s.evalEmptyInterface(dot, n) + } + case reflect.String: + return s.evalString(typ, n) + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + return s.evalUnsignedInteger(typ, n) + } + s.errorf("can't handle %s for arg of type %s", n, typ) + panic("not reached") +} + +func (s *state) evalBool(typ reflect.Type, n parse.Node) reflect.Value { + s.at(n) + if n, ok := n.(*parse.BoolNode); ok { + value := reflect.New(typ).Elem() + value.SetBool(n.True) + return value + } + s.errorf("expected bool; found %s", n) + panic("not reached") +} + +func (s *state) evalString(typ reflect.Type, n parse.Node) reflect.Value { + s.at(n) + if n, ok := n.(*parse.StringNode); ok { + value := reflect.New(typ).Elem() + value.SetString(n.Text) + return value + } + s.errorf("expected string; found %s", n) + panic("not reached") +} + +func (s *state) evalInteger(typ reflect.Type, n parse.Node) reflect.Value { + s.at(n) + if n, ok := n.(*parse.NumberNode); ok && n.IsInt { + value := reflect.New(typ).Elem() + value.SetInt(n.Int64) + return value + } + s.errorf("expected integer; found %s", n) + panic("not reached") +} + +func (s *state) evalUnsignedInteger(typ reflect.Type, n parse.Node) reflect.Value { + s.at(n) + if n, ok := n.(*parse.NumberNode); ok && n.IsUint { + value := reflect.New(typ).Elem() + value.SetUint(n.Uint64) + return value + } + s.errorf("expected unsigned integer; found %s", n) + panic("not reached") +} + +func (s *state) evalFloat(typ reflect.Type, n parse.Node) reflect.Value { + s.at(n) + if n, ok := n.(*parse.NumberNode); ok && n.IsFloat { + value := reflect.New(typ).Elem() + value.SetFloat(n.Float64) + return value + } + s.errorf("expected float; found %s", n) + panic("not reached") +} + +func (s *state) evalComplex(typ reflect.Type, n parse.Node) reflect.Value { + if n, ok := n.(*parse.NumberNode); ok && n.IsComplex { + value := reflect.New(typ).Elem() + value.SetComplex(n.Complex128) + return value + } + s.errorf("expected complex; found %s", n) + panic("not reached") +} + +func (s *state) evalEmptyInterface(dot reflect.Value, n parse.Node) reflect.Value { + s.at(n) + switch n := n.(type) { + case *parse.BoolNode: + return reflect.ValueOf(n.True) + case *parse.DotNode: + return dot + case *parse.FieldNode: + return s.evalFieldNode(dot, n, nil, zero) + case *parse.IdentifierNode: + return s.evalFunction(dot, n, n, nil, zero) + case *parse.NilNode: + // NilNode is handled in evalArg, the only place that calls here. + s.errorf("evalEmptyInterface: nil (can't happen)") + case *parse.NumberNode: + return s.idealConstant(n) + case *parse.StringNode: + return reflect.ValueOf(n.Text) + case *parse.VariableNode: + return s.evalVariableNode(dot, n, nil, zero) + case *parse.PipeNode: + return s.evalPipeline(dot, n) + } + s.errorf("can't handle assignment of %s to empty interface argument", n) + panic("not reached") +} + +// indirect returns the item at the end of indirection, and a bool to indicate if it's nil. +// We indirect through pointers and empty interfaces (only) because +// non-empty interfaces have methods we might need. +func indirect(v reflect.Value) (rv reflect.Value, isNil bool) { + for ; v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface; v = v.Elem() { + if v.IsNil() { + return v, true + } + if v.Kind() == reflect.Interface && v.NumMethod() > 0 { + break + } + } + return v, false +} + +// printValue writes the textual representation of the value to the output of +// the template. +func (s *state) printValue(n parse.Node, v reflect.Value) { + s.at(n) + iface, ok := printableValue(v) + if !ok { + s.errorf("can't print %s of type %s", n, v.Type()) + } + fmt.Fprint(s.wr, iface) +} + +// printableValue returns the, possibly indirected, interface value inside v that +// is best for a call to formatted printer. +func printableValue(v reflect.Value) (interface{}, bool) { + if v.Kind() == reflect.Ptr { + v, _ = indirect(v) // fmt.Fprint handles nil. + } + if !v.IsValid() { + return "", true + } + + if !v.Type().Implements(errorType) && !v.Type().Implements(fmtStringerType) { + if v.CanAddr() && (reflect.PtrTo(v.Type()).Implements(errorType) || reflect.PtrTo(v.Type()).Implements(fmtStringerType)) { + v = v.Addr() + } else { + switch v.Kind() { + case reflect.Chan, reflect.Func: + return nil, false + } + } + } + return v.Interface(), true +} + +// Types to help sort the keys in a map for reproducible output. + +type rvs []reflect.Value + +func (x rvs) Len() int { return len(x) } +func (x rvs) Swap(i, j int) { x[i], x[j] = x[j], x[i] } + +type rvInts struct{ rvs } + +func (x rvInts) Less(i, j int) bool { return x.rvs[i].Int() < x.rvs[j].Int() } + +type rvUints struct{ rvs } + +func (x rvUints) Less(i, j int) bool { return x.rvs[i].Uint() < x.rvs[j].Uint() } + +type rvFloats struct{ rvs } + +func (x rvFloats) Less(i, j int) bool { return x.rvs[i].Float() < x.rvs[j].Float() } + +type rvStrings struct{ rvs } + +func (x rvStrings) Less(i, j int) bool { return x.rvs[i].String() < x.rvs[j].String() } + +// sortKeys sorts (if it can) the slice of reflect.Values, which is a slice of map keys. +func sortKeys(v []reflect.Value) []reflect.Value { + if len(v) <= 1 { + return v + } + switch v[0].Kind() { + case reflect.Float32, reflect.Float64: + sort.Sort(rvFloats{v}) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + sort.Sort(rvInts{v}) + case reflect.String: + sort.Sort(rvStrings{v}) + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + sort.Sort(rvUints{v}) + } + return v +} diff --git a/src/text/template/exec_test.go b/src/text/template/exec_test.go new file mode 100644 index 000000000..663aaf3af --- /dev/null +++ b/src/text/template/exec_test.go @@ -0,0 +1,994 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package template + +import ( + "bytes" + "errors" + "flag" + "fmt" + "reflect" + "strings" + "testing" +) + +var debug = flag.Bool("debug", false, "show the errors produced by the tests") + +// T has lots of interesting pieces to use to test execution. +type T struct { + // Basics + True bool + I int + U16 uint16 + X string + FloatZero float64 + ComplexZero complex128 + // Nested structs. + U *U + // Struct with String method. + V0 V + V1, V2 *V + // Struct with Error method. + W0 W + W1, W2 *W + // Slices + SI []int + SIEmpty []int + SB []bool + // Maps + MSI map[string]int + MSIone map[string]int // one element, for deterministic output + MSIEmpty map[string]int + MXI map[interface{}]int + MII map[int]int + SMSI []map[string]int + // Empty interfaces; used to see if we can dig inside one. + Empty0 interface{} // nil + Empty1 interface{} + Empty2 interface{} + Empty3 interface{} + Empty4 interface{} + // Non-empty interface. + NonEmptyInterface I + // Stringer. + Str fmt.Stringer + Err error + // Pointers + PI *int + PS *string + PSI *[]int + NIL *int + // Function (not method) + BinaryFunc func(string, string) string + VariadicFunc func(...string) string + VariadicFuncInt func(int, ...string) string + NilOKFunc func(*int) bool + ErrFunc func() (string, error) + // Template to test evaluation of templates. + Tmpl *Template + // Unexported field; cannot be accessed by template. + unexported int +} + +type U struct { + V string +} + +type V struct { + j int +} + +func (v *V) String() string { + if v == nil { + return "nilV" + } + return fmt.Sprintf("<%d>", v.j) +} + +type W struct { + k int +} + +func (w *W) Error() string { + if w == nil { + return "nilW" + } + return fmt.Sprintf("[%d]", w.k) +} + +var tVal = &T{ + True: true, + I: 17, + U16: 16, + X: "x", + U: &U{"v"}, + V0: V{6666}, + V1: &V{7777}, // leave V2 as nil + W0: W{888}, + W1: &W{999}, // leave W2 as nil + SI: []int{3, 4, 5}, + SB: []bool{true, false}, + MSI: map[string]int{"one": 1, "two": 2, "three": 3}, + MSIone: map[string]int{"one": 1}, + MXI: map[interface{}]int{"one": 1}, + MII: map[int]int{1: 1}, + SMSI: []map[string]int{ + {"one": 1, "two": 2}, + {"eleven": 11, "twelve": 12}, + }, + Empty1: 3, + Empty2: "empty2", + Empty3: []int{7, 8}, + Empty4: &U{"UinEmpty"}, + NonEmptyInterface: new(T), + Str: bytes.NewBuffer([]byte("foozle")), + Err: errors.New("erroozle"), + PI: newInt(23), + PS: newString("a string"), + PSI: newIntSlice(21, 22, 23), + BinaryFunc: func(a, b string) string { return fmt.Sprintf("[%s=%s]", a, b) }, + VariadicFunc: func(s ...string) string { return fmt.Sprint("<", strings.Join(s, "+"), ">") }, + VariadicFuncInt: func(a int, s ...string) string { return fmt.Sprint(a, "=<", strings.Join(s, "+"), ">") }, + NilOKFunc: func(s *int) bool { return s == nil }, + ErrFunc: func() (string, error) { return "bla", nil }, + Tmpl: Must(New("x").Parse("test template")), // "x" is the value of .X +} + +// A non-empty interface. +type I interface { + Method0() string +} + +var iVal I = tVal + +// Helpers for creation. +func newInt(n int) *int { + return &n +} + +func newString(s string) *string { + return &s +} + +func newIntSlice(n ...int) *[]int { + p := new([]int) + *p = make([]int, len(n)) + copy(*p, n) + return p +} + +// Simple methods with and without arguments. +func (t *T) Method0() string { + return "M0" +} + +func (t *T) Method1(a int) int { + return a +} + +func (t *T) Method2(a uint16, b string) string { + return fmt.Sprintf("Method2: %d %s", a, b) +} + +func (t *T) Method3(v interface{}) string { + return fmt.Sprintf("Method3: %v", v) +} + +func (t *T) MAdd(a int, b []int) []int { + v := make([]int, len(b)) + for i, x := range b { + v[i] = x + a + } + return v +} + +var myError = errors.New("my error") + +// MyError returns a value and an error according to its argument. +func (t *T) MyError(error bool) (bool, error) { + if error { + return true, myError + } + return false, nil +} + +// A few methods to test chaining. +func (t *T) GetU() *U { + return t.U +} + +func (u *U) TrueFalse(b bool) string { + if b { + return "true" + } + return "" +} + +func typeOf(arg interface{}) string { + return fmt.Sprintf("%T", arg) +} + +type execTest struct { + name string + input string + output string + data interface{} + ok bool +} + +// bigInt and bigUint are hex string representing numbers either side +// of the max int boundary. +// We do it this way so the test doesn't depend on ints being 32 bits. +var ( + bigInt = fmt.Sprintf("0x%x", int(1<", tVal, true}, + {"map .one interface", "{{.MXI.one}}", "1", tVal, true}, + {"map .WRONG args", "{{.MSI.one 1}}", "", tVal, false}, + {"map .WRONG type", "{{.MII.one}}", "", tVal, false}, + + // Dots of all kinds to test basic evaluation. + {"dot int", "<{{.}}>", "<13>", 13, true}, + {"dot uint", "<{{.}}>", "<14>", uint(14), true}, + {"dot float", "<{{.}}>", "<15.1>", 15.1, true}, + {"dot bool", "<{{.}}>", "", true, true}, + {"dot complex", "<{{.}}>", "<(16.2-17i)>", 16.2 - 17i, true}, + {"dot string", "<{{.}}>", "", "hello", true}, + {"dot slice", "<{{.}}>", "<[-1 -2 -3]>", []int{-1, -2, -3}, true}, + {"dot map", "<{{.}}>", "", map[string]int{"two": 22}, true}, + {"dot struct", "<{{.}}>", "<{7 seven}>", struct { + a int + b string + }{7, "seven"}, true}, + + // Variables. + {"$ int", "{{$}}", "123", 123, true}, + {"$.I", "{{$.I}}", "17", tVal, true}, + {"$.U.V", "{{$.U.V}}", "v", tVal, true}, + {"declare in action", "{{$x := $.U.V}}{{$x}}", "v", tVal, true}, + + // Type with String method. + {"V{6666}.String()", "-{{.V0}}-", "-<6666>-", tVal, true}, + {"&V{7777}.String()", "-{{.V1}}-", "-<7777>-", tVal, true}, + {"(*V)(nil).String()", "-{{.V2}}-", "-nilV-", tVal, true}, + + // Type with Error method. + {"W{888}.Error()", "-{{.W0}}-", "-[888]-", tVal, true}, + {"&W{999}.Error()", "-{{.W1}}-", "-[999]-", tVal, true}, + {"(*W)(nil).Error()", "-{{.W2}}-", "-nilW-", tVal, true}, + + // Pointers. + {"*int", "{{.PI}}", "23", tVal, true}, + {"*string", "{{.PS}}", "a string", tVal, true}, + {"*[]int", "{{.PSI}}", "[21 22 23]", tVal, true}, + {"*[]int[1]", "{{index .PSI 1}}", "22", tVal, true}, + {"NIL", "{{.NIL}}", "", tVal, true}, + + // Empty interfaces holding values. + {"empty nil", "{{.Empty0}}", "", tVal, true}, + {"empty with int", "{{.Empty1}}", "3", tVal, true}, + {"empty with string", "{{.Empty2}}", "empty2", tVal, true}, + {"empty with slice", "{{.Empty3}}", "[7 8]", tVal, true}, + {"empty with struct", "{{.Empty4}}", "{UinEmpty}", tVal, true}, + {"empty with struct, field", "{{.Empty4.V}}", "UinEmpty", tVal, true}, + + // Method calls. + {".Method0", "-{{.Method0}}-", "-M0-", tVal, true}, + {".Method1(1234)", "-{{.Method1 1234}}-", "-1234-", tVal, true}, + {".Method1(.I)", "-{{.Method1 .I}}-", "-17-", tVal, true}, + {".Method2(3, .X)", "-{{.Method2 3 .X}}-", "-Method2: 3 x-", tVal, true}, + {".Method2(.U16, `str`)", "-{{.Method2 .U16 `str`}}-", "-Method2: 16 str-", tVal, true}, + {".Method2(.U16, $x)", "{{if $x := .X}}-{{.Method2 .U16 $x}}{{end}}-", "-Method2: 16 x-", tVal, true}, + {".Method3(nil constant)", "-{{.Method3 nil}}-", "-Method3: -", tVal, true}, + {".Method3(nil value)", "-{{.Method3 .MXI.unset}}-", "-Method3: -", tVal, true}, + {"method on var", "{{if $x := .}}-{{$x.Method2 .U16 $x.X}}{{end}}-", "-Method2: 16 x-", tVal, true}, + {"method on chained var", + "{{range .MSIone}}{{if $.U.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}", + "true", tVal, true}, + {"chained method", + "{{range .MSIone}}{{if $.GetU.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}", + "true", tVal, true}, + {"chained method on variable", + "{{with $x := .}}{{with .SI}}{{$.GetU.TrueFalse $.True}}{{end}}{{end}}", + "true", tVal, true}, + {".NilOKFunc not nil", "{{call .NilOKFunc .PI}}", "false", tVal, true}, + {".NilOKFunc nil", "{{call .NilOKFunc nil}}", "true", tVal, true}, + + // Function call builtin. + {".BinaryFunc", "{{call .BinaryFunc `1` `2`}}", "[1=2]", tVal, true}, + {".VariadicFunc0", "{{call .VariadicFunc}}", "<>", tVal, true}, + {".VariadicFunc2", "{{call .VariadicFunc `he` `llo`}}", "", tVal, true}, + {".VariadicFuncInt", "{{call .VariadicFuncInt 33 `he` `llo`}}", "33=", tVal, true}, + {"if .BinaryFunc call", "{{ if .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{end}}", "[1=2]", tVal, true}, + {"if not .BinaryFunc call", "{{ if not .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{else}}No{{end}}", "No", tVal, true}, + {"Interface Call", `{{stringer .S}}`, "foozle", map[string]interface{}{"S": bytes.NewBufferString("foozle")}, true}, + {".ErrFunc", "{{call .ErrFunc}}", "bla", tVal, true}, + + // Erroneous function calls (check args). + {".BinaryFuncTooFew", "{{call .BinaryFunc `1`}}", "", tVal, false}, + {".BinaryFuncTooMany", "{{call .BinaryFunc `1` `2` `3`}}", "", tVal, false}, + {".BinaryFuncBad0", "{{call .BinaryFunc 1 3}}", "", tVal, false}, + {".BinaryFuncBad1", "{{call .BinaryFunc `1` 3}}", "", tVal, false}, + {".VariadicFuncBad0", "{{call .VariadicFunc 3}}", "", tVal, false}, + {".VariadicFuncIntBad0", "{{call .VariadicFuncInt}}", "", tVal, false}, + {".VariadicFuncIntBad`", "{{call .VariadicFuncInt `x`}}", "", tVal, false}, + {".VariadicFuncNilBad", "{{call .VariadicFunc nil}}", "", tVal, false}, + + // Pipelines. + {"pipeline", "-{{.Method0 | .Method2 .U16}}-", "-Method2: 16 M0-", tVal, true}, + {"pipeline func", "-{{call .VariadicFunc `llo` | call .VariadicFunc `he` }}-", "->-", tVal, true}, + + // Parenthesized expressions + {"parens in pipeline", "{{printf `%d %d %d` (1) (2 | add 3) (add 4 (add 5 6))}}", "1 5 15", tVal, true}, + + // Parenthesized expressions with field accesses + {"parens: $ in paren", "{{($).X}}", "x", tVal, true}, + {"parens: $.GetU in paren", "{{($.GetU).V}}", "v", tVal, true}, + {"parens: $ in paren in pipe", "{{($ | echo).X}}", "x", tVal, true}, + {"parens: spaces and args", `{{(makemap "up" "down" "left" "right").left}}`, "right", tVal, true}, + + // If. + {"if true", "{{if true}}TRUE{{end}}", "TRUE", tVal, true}, + {"if false", "{{if false}}TRUE{{else}}FALSE{{end}}", "FALSE", tVal, true}, + {"if nil", "{{if nil}}TRUE{{end}}", "", tVal, false}, + {"if 1", "{{if 1}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true}, + {"if 0", "{{if 0}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true}, + {"if 1.5", "{{if 1.5}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true}, + {"if 0.0", "{{if .FloatZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true}, + {"if 1.5i", "{{if 1.5i}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true}, + {"if 0.0i", "{{if .ComplexZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true}, + {"if emptystring", "{{if ``}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true}, + {"if string", "{{if `notempty`}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true}, + {"if emptyslice", "{{if .SIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true}, + {"if slice", "{{if .SI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true}, + {"if emptymap", "{{if .MSIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true}, + {"if map", "{{if .MSI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true}, + {"if map unset", "{{if .MXI.none}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true}, + {"if map not unset", "{{if not .MXI.none}}ZERO{{else}}NON-ZERO{{end}}", "ZERO", tVal, true}, + {"if $x with $y int", "{{if $x := true}}{{with $y := .I}}{{$x}},{{$y}}{{end}}{{end}}", "true,17", tVal, true}, + {"if $x with $x int", "{{if $x := true}}{{with $x := .I}}{{$x}},{{end}}{{$x}}{{end}}", "17,true", tVal, true}, + {"if else if", "{{if false}}FALSE{{else if true}}TRUE{{end}}", "TRUE", tVal, true}, + {"if else chain", "{{if eq 1 3}}1{{else if eq 2 3}}2{{else if eq 3 3}}3{{end}}", "3", tVal, true}, + + // Print etc. + {"print", `{{print "hello, print"}}`, "hello, print", tVal, true}, + {"print 123", `{{print 1 2 3}}`, "1 2 3", tVal, true}, + {"print nil", `{{print nil}}`, "", tVal, true}, + {"println", `{{println 1 2 3}}`, "1 2 3\n", tVal, true}, + {"printf int", `{{printf "%04x" 127}}`, "007f", tVal, true}, + {"printf float", `{{printf "%g" 3.5}}`, "3.5", tVal, true}, + {"printf complex", `{{printf "%g" 1+7i}}`, "(1+7i)", tVal, true}, + {"printf string", `{{printf "%s" "hello"}}`, "hello", tVal, true}, + {"printf function", `{{printf "%#q" zeroArgs}}`, "`zeroArgs`", tVal, true}, + {"printf field", `{{printf "%s" .U.V}}`, "v", tVal, true}, + {"printf method", `{{printf "%s" .Method0}}`, "M0", tVal, true}, + {"printf dot", `{{with .I}}{{printf "%d" .}}{{end}}`, "17", tVal, true}, + {"printf var", `{{with $x := .I}}{{printf "%d" $x}}{{end}}`, "17", tVal, true}, + {"printf lots", `{{printf "%d %s %g %s" 127 "hello" 7-3i .Method0}}`, "127 hello (7-3i) M0", tVal, true}, + + // HTML. + {"html", `{{html ""}}`, + "<script>alert("XSS");</script>", nil, true}, + {"html pipeline", `{{printf "" | html}}`, + "<script>alert("XSS");</script>", nil, true}, + {"html", `{{html .PS}}`, "a string", tVal, true}, + + // JavaScript. + {"js", `{{js .}}`, `It\'d be nice.`, `It'd be nice.`, true}, + + // URL query. + {"urlquery", `{{"http://www.example.org/"|urlquery}}`, "http%3A%2F%2Fwww.example.org%2F", nil, true}, + + // Booleans + {"not", "{{not true}} {{not false}}", "false true", nil, true}, + {"and", "{{and false 0}} {{and 1 0}} {{and 0 true}} {{and 1 1}}", "false 0 0 1", nil, true}, + {"or", "{{or 0 0}} {{or 1 0}} {{or 0 true}} {{or 1 1}}", "0 1 true 1", nil, true}, + {"boolean if", "{{if and true 1 `hi`}}TRUE{{else}}FALSE{{end}}", "TRUE", tVal, true}, + {"boolean if not", "{{if and true 1 `hi` | not}}TRUE{{else}}FALSE{{end}}", "FALSE", nil, true}, + + // Indexing. + {"slice[0]", "{{index .SI 0}}", "3", tVal, true}, + {"slice[1]", "{{index .SI 1}}", "4", tVal, true}, + {"slice[HUGE]", "{{index .SI 10}}", "", tVal, false}, + {"slice[WRONG]", "{{index .SI `hello`}}", "", tVal, false}, + {"map[one]", "{{index .MSI `one`}}", "1", tVal, true}, + {"map[two]", "{{index .MSI `two`}}", "2", tVal, true}, + {"map[NO]", "{{index .MSI `XXX`}}", "0", tVal, true}, + {"map[nil]", "{{index .MSI nil}}", "0", tVal, true}, + {"map[WRONG]", "{{index .MSI 10}}", "", tVal, false}, + {"double index", "{{index .SMSI 1 `eleven`}}", "11", tVal, true}, + + // Len. + {"slice", "{{len .SI}}", "3", tVal, true}, + {"map", "{{len .MSI }}", "3", tVal, true}, + {"len of int", "{{len 3}}", "", tVal, false}, + {"len of nothing", "{{len .Empty0}}", "", tVal, false}, + + // With. + {"with true", "{{with true}}{{.}}{{end}}", "true", tVal, true}, + {"with false", "{{with false}}{{.}}{{else}}FALSE{{end}}", "FALSE", tVal, true}, + {"with 1", "{{with 1}}{{.}}{{else}}ZERO{{end}}", "1", tVal, true}, + {"with 0", "{{with 0}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true}, + {"with 1.5", "{{with 1.5}}{{.}}{{else}}ZERO{{end}}", "1.5", tVal, true}, + {"with 0.0", "{{with .FloatZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true}, + {"with 1.5i", "{{with 1.5i}}{{.}}{{else}}ZERO{{end}}", "(0+1.5i)", tVal, true}, + {"with 0.0i", "{{with .ComplexZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true}, + {"with emptystring", "{{with ``}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true}, + {"with string", "{{with `notempty`}}{{.}}{{else}}EMPTY{{end}}", "notempty", tVal, true}, + {"with emptyslice", "{{with .SIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true}, + {"with slice", "{{with .SI}}{{.}}{{else}}EMPTY{{end}}", "[3 4 5]", tVal, true}, + {"with emptymap", "{{with .MSIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true}, + {"with map", "{{with .MSIone}}{{.}}{{else}}EMPTY{{end}}", "map[one:1]", tVal, true}, + {"with empty interface, struct field", "{{with .Empty4}}{{.V}}{{end}}", "UinEmpty", tVal, true}, + {"with $x int", "{{with $x := .I}}{{$x}}{{end}}", "17", tVal, true}, + {"with $x struct.U.V", "{{with $x := $}}{{$x.U.V}}{{end}}", "v", tVal, true}, + {"with variable and action", "{{with $x := $}}{{$y := $.U.V}}{{$y}}{{end}}", "v", tVal, true}, + + // Range. + {"range []int", "{{range .SI}}-{{.}}-{{end}}", "-3--4--5-", tVal, true}, + {"range empty no else", "{{range .SIEmpty}}-{{.}}-{{end}}", "", tVal, true}, + {"range []int else", "{{range .SI}}-{{.}}-{{else}}EMPTY{{end}}", "-3--4--5-", tVal, true}, + {"range empty else", "{{range .SIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true}, + {"range []bool", "{{range .SB}}-{{.}}-{{end}}", "-true--false-", tVal, true}, + {"range []int method", "{{range .SI | .MAdd .I}}-{{.}}-{{end}}", "-20--21--22-", tVal, true}, + {"range map", "{{range .MSI}}-{{.}}-{{end}}", "-1--3--2-", tVal, true}, + {"range empty map no else", "{{range .MSIEmpty}}-{{.}}-{{end}}", "", tVal, true}, + {"range map else", "{{range .MSI}}-{{.}}-{{else}}EMPTY{{end}}", "-1--3--2-", tVal, true}, + {"range empty map else", "{{range .MSIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true}, + {"range empty interface", "{{range .Empty3}}-{{.}}-{{else}}EMPTY{{end}}", "-7--8-", tVal, true}, + {"range empty nil", "{{range .Empty0}}-{{.}}-{{end}}", "", tVal, true}, + {"range $x SI", "{{range $x := .SI}}<{{$x}}>{{end}}", "<3><4><5>", tVal, true}, + {"range $x $y SI", "{{range $x, $y := .SI}}<{{$x}}={{$y}}>{{end}}", "<0=3><1=4><2=5>", tVal, true}, + {"range $x MSIone", "{{range $x := .MSIone}}<{{$x}}>{{end}}", "<1>", tVal, true}, + {"range $x $y MSIone", "{{range $x, $y := .MSIone}}<{{$x}}={{$y}}>{{end}}", "", tVal, true}, + {"range $x PSI", "{{range $x := .PSI}}<{{$x}}>{{end}}", "<21><22><23>", tVal, true}, + {"declare in range", "{{range $x := .PSI}}<{{$foo:=$x}}{{$x}}>{{end}}", "<21><22><23>", tVal, true}, + {"range count", `{{range $i, $x := count 5}}[{{$i}}]{{$x}}{{end}}`, "[0]a[1]b[2]c[3]d[4]e", tVal, true}, + {"range nil count", `{{range $i, $x := count 0}}{{else}}empty{{end}}`, "empty", tVal, true}, + + // Cute examples. + {"or as if true", `{{or .SI "slice is empty"}}`, "[3 4 5]", tVal, true}, + {"or as if false", `{{or .SIEmpty "slice is empty"}}`, "slice is empty", tVal, true}, + + // Error handling. + {"error method, error", "{{.MyError true}}", "", tVal, false}, + {"error method, no error", "{{.MyError false}}", "false", tVal, true}, + + // Fixed bugs. + // Must separate dot and receiver; otherwise args are evaluated with dot set to variable. + {"bug0", "{{range .MSIone}}{{if $.Method1 .}}X{{end}}{{end}}", "X", tVal, true}, + // Do not loop endlessly in indirect for non-empty interfaces. + // The bug appears with *interface only; looped forever. + {"bug1", "{{.Method0}}", "M0", &iVal, true}, + // Was taking address of interface field, so method set was empty. + {"bug2", "{{$.NonEmptyInterface.Method0}}", "M0", tVal, true}, + // Struct values were not legal in with - mere oversight. + {"bug3", "{{with $}}{{.Method0}}{{end}}", "M0", tVal, true}, + // Nil interface values in if. + {"bug4", "{{if .Empty0}}non-nil{{else}}nil{{end}}", "nil", tVal, true}, + // Stringer. + {"bug5", "{{.Str}}", "foozle", tVal, true}, + {"bug5a", "{{.Err}}", "erroozle", tVal, true}, + // Args need to be indirected and dereferenced sometimes. + {"bug6a", "{{vfunc .V0 .V1}}", "vfunc", tVal, true}, + {"bug6b", "{{vfunc .V0 .V0}}", "vfunc", tVal, true}, + {"bug6c", "{{vfunc .V1 .V0}}", "vfunc", tVal, true}, + {"bug6d", "{{vfunc .V1 .V1}}", "vfunc", tVal, true}, + // Legal parse but illegal execution: non-function should have no arguments. + {"bug7a", "{{3 2}}", "", tVal, false}, + {"bug7b", "{{$x := 1}}{{$x 2}}", "", tVal, false}, + {"bug7c", "{{$x := 1}}{{3 | $x}}", "", tVal, false}, + // Pipelined arg was not being type-checked. + {"bug8a", "{{3|oneArg}}", "", tVal, false}, + {"bug8b", "{{4|dddArg 3}}", "", tVal, false}, + // A bug was introduced that broke map lookups for lower-case names. + {"bug9", "{{.cause}}", "neglect", map[string]string{"cause": "neglect"}, true}, + // Field chain starting with function did not work. + {"bug10", "{{mapOfThree.three}}-{{(mapOfThree).three}}", "3-3", 0, true}, + // Dereferencing nil pointer while evaluating function arguments should not panic. Issue 7333. + {"bug11", "{{valueString .PS}}", "", T{}, false}, + // 0xef gave constant type float64. Issue 8622. + {"bug12xe", "{{printf `%T` 0xef}}", "int", T{}, true}, + {"bug12xE", "{{printf `%T` 0xEE}}", "int", T{}, true}, + {"bug12Xe", "{{printf `%T` 0Xef}}", "int", T{}, true}, + {"bug12XE", "{{printf `%T` 0XEE}}", "int", T{}, true}, +} + +func zeroArgs() string { + return "zeroArgs" +} + +func oneArg(a string) string { + return "oneArg=" + a +} + +func dddArg(a int, b ...string) string { + return fmt.Sprintln(a, b) +} + +// count returns a channel that will deliver n sequential 1-letter strings starting at "a" +func count(n int) chan string { + if n == 0 { + return nil + } + c := make(chan string) + go func() { + for i := 0; i < n; i++ { + c <- "abcdefghijklmnop"[i : i+1] + } + close(c) + }() + return c +} + +// vfunc takes a *V and a V +func vfunc(V, *V) string { + return "vfunc" +} + +// valueString takes a string, not a pointer. +func valueString(v string) string { + return "value is ignored" +} + +func add(args ...int) int { + sum := 0 + for _, x := range args { + sum += x + } + return sum +} + +func echo(arg interface{}) interface{} { + return arg +} + +func makemap(arg ...string) map[string]string { + if len(arg)%2 != 0 { + panic("bad makemap") + } + m := make(map[string]string) + for i := 0; i < len(arg); i += 2 { + m[arg[i]] = arg[i+1] + } + return m +} + +func stringer(s fmt.Stringer) string { + return s.String() +} + +func mapOfThree() interface{} { + return map[string]int{"three": 3} +} + +func testExecute(execTests []execTest, template *Template, t *testing.T) { + b := new(bytes.Buffer) + funcs := FuncMap{ + "add": add, + "count": count, + "dddArg": dddArg, + "echo": echo, + "makemap": makemap, + "mapOfThree": mapOfThree, + "oneArg": oneArg, + "stringer": stringer, + "typeOf": typeOf, + "valueString": valueString, + "vfunc": vfunc, + "zeroArgs": zeroArgs, + } + for _, test := range execTests { + var tmpl *Template + var err error + if template == nil { + tmpl, err = New(test.name).Funcs(funcs).Parse(test.input) + } else { + tmpl, err = template.New(test.name).Funcs(funcs).Parse(test.input) + } + if err != nil { + t.Errorf("%s: parse error: %s", test.name, err) + continue + } + b.Reset() + err = tmpl.Execute(b, test.data) + switch { + case !test.ok && err == nil: + t.Errorf("%s: expected error; got none", test.name) + continue + case test.ok && err != nil: + t.Errorf("%s: unexpected execute error: %s", test.name, err) + continue + case !test.ok && err != nil: + // expected error, got one + if *debug { + fmt.Printf("%s: %s\n\t%s\n", test.name, test.input, err) + } + } + result := b.String() + if result != test.output { + t.Errorf("%s: expected\n\t%q\ngot\n\t%q", test.name, test.output, result) + } + } +} + +func TestExecute(t *testing.T) { + testExecute(execTests, nil, t) +} + +var delimPairs = []string{ + "", "", // default + "{{", "}}", // same as default + "<<", ">>", // distinct + "|", "|", // same + "(日)", "(本)", // peculiar +} + +func TestDelims(t *testing.T) { + const hello = "Hello, world" + var value = struct{ Str string }{hello} + for i := 0; i < len(delimPairs); i += 2 { + text := ".Str" + left := delimPairs[i+0] + trueLeft := left + right := delimPairs[i+1] + trueRight := right + if left == "" { // default case + trueLeft = "{{" + } + if right == "" { // default case + trueRight = "}}" + } + text = trueLeft + text + trueRight + // Now add a comment + text += trueLeft + "/*comment*/" + trueRight + // Now add an action containing a string. + text += trueLeft + `"` + trueLeft + `"` + trueRight + // At this point text looks like `{{.Str}}{{/*comment*/}}{{"{{"}}`. + tmpl, err := New("delims").Delims(left, right).Parse(text) + if err != nil { + t.Fatalf("delim %q text %q parse err %s", left, text, err) + } + var b = new(bytes.Buffer) + err = tmpl.Execute(b, value) + if err != nil { + t.Fatalf("delim %q exec err %s", left, err) + } + if b.String() != hello+trueLeft { + t.Errorf("expected %q got %q", hello+trueLeft, b.String()) + } + } +} + +// Check that an error from a method flows back to the top. +func TestExecuteError(t *testing.T) { + b := new(bytes.Buffer) + tmpl := New("error") + _, err := tmpl.Parse("{{.MyError true}}") + if err != nil { + t.Fatalf("parse error: %s", err) + } + err = tmpl.Execute(b, tVal) + if err == nil { + t.Errorf("expected error; got none") + } else if !strings.Contains(err.Error(), myError.Error()) { + if *debug { + fmt.Printf("test execute error: %s\n", err) + } + t.Errorf("expected myError; got %s", err) + } +} + +const execErrorText = `line 1 +line 2 +line 3 +{{template "one" .}} +{{define "one"}}{{template "two" .}}{{end}} +{{define "two"}}{{template "three" .}}{{end}} +{{define "three"}}{{index "hi" $}}{{end}}` + +// Check that an error from a nested template contains all the relevant information. +func TestExecError(t *testing.T) { + tmpl, err := New("top").Parse(execErrorText) + if err != nil { + t.Fatal("parse error:", err) + } + var b bytes.Buffer + err = tmpl.Execute(&b, 5) // 5 is out of range indexing "hi" + if err == nil { + t.Fatal("expected error") + } + const want = `template: top:7:20: executing "three" at : error calling index: index out of range: 5` + got := err.Error() + if got != want { + t.Errorf("expected\n%q\ngot\n%q", want, got) + } +} + +func TestJSEscaping(t *testing.T) { + testCases := []struct { + in, exp string + }{ + {`a`, `a`}, + {`'foo`, `\'foo`}, + {`Go "jump" \`, `Go \"jump\" \\`}, + {`Yukihiro says "今日は世界"`, `Yukihiro says \"今日は世界\"`}, + {"unprintable \uFDFF", `unprintable \uFDFF`}, + {``, `\x3Chtml\x3E`}, + } + for _, tc := range testCases { + s := JSEscapeString(tc.in) + if s != tc.exp { + t.Errorf("JS escaping [%s] got [%s] want [%s]", tc.in, s, tc.exp) + } + } +} + +// A nice example: walk a binary tree. + +type Tree struct { + Val int + Left, Right *Tree +} + +// Use different delimiters to test Set.Delims. +const treeTemplate = ` + (define "tree") + [ + (.Val) + (with .Left) + (template "tree" .) + (end) + (with .Right) + (template "tree" .) + (end) + ] + (end) +` + +func TestTree(t *testing.T) { + var tree = &Tree{ + 1, + &Tree{ + 2, &Tree{ + 3, + &Tree{ + 4, nil, nil, + }, + nil, + }, + &Tree{ + 5, + &Tree{ + 6, nil, nil, + }, + nil, + }, + }, + &Tree{ + 7, + &Tree{ + 8, + &Tree{ + 9, nil, nil, + }, + nil, + }, + &Tree{ + 10, + &Tree{ + 11, nil, nil, + }, + nil, + }, + }, + } + tmpl, err := New("root").Delims("(", ")").Parse(treeTemplate) + if err != nil { + t.Fatal("parse error:", err) + } + var b bytes.Buffer + stripSpace := func(r rune) rune { + if r == '\t' || r == '\n' { + return -1 + } + return r + } + const expect = "[1[2[3[4]][5[6]]][7[8[9]][10[11]]]]" + // First by looking up the template. + err = tmpl.Lookup("tree").Execute(&b, tree) + if err != nil { + t.Fatal("exec error:", err) + } + result := strings.Map(stripSpace, b.String()) + if result != expect { + t.Errorf("expected %q got %q", expect, result) + } + // Then direct to execution. + b.Reset() + err = tmpl.ExecuteTemplate(&b, "tree", tree) + if err != nil { + t.Fatal("exec error:", err) + } + result = strings.Map(stripSpace, b.String()) + if result != expect { + t.Errorf("expected %q got %q", expect, result) + } +} + +func TestExecuteOnNewTemplate(t *testing.T) { + // This is issue 3872. + _ = New("Name").Templates() +} + +const testTemplates = `{{define "one"}}one{{end}}{{define "two"}}two{{end}}` + +func TestMessageForExecuteEmpty(t *testing.T) { + // Test a truly empty template. + tmpl := New("empty") + var b bytes.Buffer + err := tmpl.Execute(&b, 0) + if err == nil { + t.Fatal("expected initial error") + } + got := err.Error() + want := `template: empty: "empty" is an incomplete or empty template` + if got != want { + t.Errorf("expected error %s got %s", want, got) + } + // Add a non-empty template to check that the error is helpful. + tests, err := New("").Parse(testTemplates) + if err != nil { + t.Fatal(err) + } + tmpl.AddParseTree("secondary", tests.Tree) + err = tmpl.Execute(&b, 0) + if err == nil { + t.Fatal("expected second error") + } + got = err.Error() + want = `template: empty: "empty" is an incomplete or empty template; defined templates are: "secondary"` + if got != want { + t.Errorf("expected error %s got %s", want, got) + } + // Make sure we can execute the secondary. + err = tmpl.ExecuteTemplate(&b, "secondary", 0) + if err != nil { + t.Fatal(err) + } +} + +type cmpTest struct { + expr string + truth string + ok bool +} + +var cmpTests = []cmpTest{ + {"eq true true", "true", true}, + {"eq true false", "false", true}, + {"eq 1+2i 1+2i", "true", true}, + {"eq 1+2i 1+3i", "false", true}, + {"eq 1.5 1.5", "true", true}, + {"eq 1.5 2.5", "false", true}, + {"eq 1 1", "true", true}, + {"eq 1 2", "false", true}, + {"eq `xy` `xy`", "true", true}, + {"eq `xy` `xyz`", "false", true}, + {"eq .Xuint .Xuint", "true", true}, + {"eq .Xuint .Yuint", "false", true}, + {"eq 3 4 5 6 3", "true", true}, + {"eq 3 4 5 6 7", "false", true}, + {"ne true true", "false", true}, + {"ne true false", "true", true}, + {"ne 1+2i 1+2i", "false", true}, + {"ne 1+2i 1+3i", "true", true}, + {"ne 1.5 1.5", "false", true}, + {"ne 1.5 2.5", "true", true}, + {"ne 1 1", "false", true}, + {"ne 1 2", "true", true}, + {"ne `xy` `xy`", "false", true}, + {"ne `xy` `xyz`", "true", true}, + {"ne .Xuint .Xuint", "false", true}, + {"ne .Xuint .Yuint", "true", true}, + {"lt 1.5 1.5", "false", true}, + {"lt 1.5 2.5", "true", true}, + {"lt 1 1", "false", true}, + {"lt 1 2", "true", true}, + {"lt `xy` `xy`", "false", true}, + {"lt `xy` `xyz`", "true", true}, + {"lt .Xuint .Xuint", "false", true}, + {"lt .Xuint .Yuint", "true", true}, + {"le 1.5 1.5", "true", true}, + {"le 1.5 2.5", "true", true}, + {"le 2.5 1.5", "false", true}, + {"le 1 1", "true", true}, + {"le 1 2", "true", true}, + {"le 2 1", "false", true}, + {"le `xy` `xy`", "true", true}, + {"le `xy` `xyz`", "true", true}, + {"le `xyz` `xy`", "false", true}, + {"le .Xuint .Xuint", "true", true}, + {"le .Xuint .Yuint", "true", true}, + {"le .Yuint .Xuint", "false", true}, + {"gt 1.5 1.5", "false", true}, + {"gt 1.5 2.5", "false", true}, + {"gt 1 1", "false", true}, + {"gt 2 1", "true", true}, + {"gt 1 2", "false", true}, + {"gt `xy` `xy`", "false", true}, + {"gt `xy` `xyz`", "false", true}, + {"gt .Xuint .Xuint", "false", true}, + {"gt .Xuint .Yuint", "false", true}, + {"gt .Yuint .Xuint", "true", true}, + {"ge 1.5 1.5", "true", true}, + {"ge 1.5 2.5", "false", true}, + {"ge 2.5 1.5", "true", true}, + {"ge 1 1", "true", true}, + {"ge 1 2", "false", true}, + {"ge 2 1", "true", true}, + {"ge `xy` `xy`", "true", true}, + {"ge `xy` `xyz`", "false", true}, + {"ge `xyz` `xy`", "true", true}, + {"ge .Xuint .Xuint", "true", true}, + {"ge .Xuint .Yuint", "false", true}, + {"ge .Yuint .Xuint", "true", true}, + // Errors + {"eq `xy` 1", "", false}, // Different types. + {"lt true true", "", false}, // Unordered types. + {"lt 1+0i 1+0i", "", false}, // Unordered types. +} + +func TestComparison(t *testing.T) { + b := new(bytes.Buffer) + var cmpStruct = struct { + Xuint, Yuint uint + }{3, 4} + for _, test := range cmpTests { + text := fmt.Sprintf("{{if %s}}true{{else}}false{{end}}", test.expr) + tmpl, err := New("empty").Parse(text) + if err != nil { + t.Fatal(err) + } + b.Reset() + err = tmpl.Execute(b, &cmpStruct) + if test.ok && err != nil { + t.Errorf("%s errored incorrectly: %s", test.expr, err) + continue + } + if !test.ok && err == nil { + t.Errorf("%s did not error", test.expr) + continue + } + if b.String() != test.truth { + t.Errorf("%s: want %s; got %s", test.expr, test.truth, b.String()) + } + } +} diff --git a/src/text/template/funcs.go b/src/text/template/funcs.go new file mode 100644 index 000000000..e85412262 --- /dev/null +++ b/src/text/template/funcs.go @@ -0,0 +1,580 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package template + +import ( + "bytes" + "errors" + "fmt" + "io" + "net/url" + "reflect" + "strings" + "unicode" + "unicode/utf8" +) + +// FuncMap is the type of the map defining the mapping from names to functions. +// Each function must have either a single return value, or two return values of +// which the second has type error. In that case, if the second (error) +// return value evaluates to non-nil during execution, execution terminates and +// Execute returns that error. +type FuncMap map[string]interface{} + +var builtins = FuncMap{ + "and": and, + "call": call, + "html": HTMLEscaper, + "index": index, + "js": JSEscaper, + "len": length, + "not": not, + "or": or, + "print": fmt.Sprint, + "printf": fmt.Sprintf, + "println": fmt.Sprintln, + "urlquery": URLQueryEscaper, + + // Comparisons + "eq": eq, // == + "ge": ge, // >= + "gt": gt, // > + "le": le, // <= + "lt": lt, // < + "ne": ne, // != +} + +var builtinFuncs = createValueFuncs(builtins) + +// createValueFuncs turns a FuncMap into a map[string]reflect.Value +func createValueFuncs(funcMap FuncMap) map[string]reflect.Value { + m := make(map[string]reflect.Value) + addValueFuncs(m, funcMap) + return m +} + +// addValueFuncs adds to values the functions in funcs, converting them to reflect.Values. +func addValueFuncs(out map[string]reflect.Value, in FuncMap) { + for name, fn := range in { + v := reflect.ValueOf(fn) + if v.Kind() != reflect.Func { + panic("value for " + name + " not a function") + } + if !goodFunc(v.Type()) { + panic(fmt.Errorf("can't install method/function %q with %d results", name, v.Type().NumOut())) + } + out[name] = v + } +} + +// addFuncs adds to values the functions in funcs. It does no checking of the input - +// call addValueFuncs first. +func addFuncs(out, in FuncMap) { + for name, fn := range in { + out[name] = fn + } +} + +// goodFunc checks that the function or method has the right result signature. +func goodFunc(typ reflect.Type) bool { + // We allow functions with 1 result or 2 results where the second is an error. + switch { + case typ.NumOut() == 1: + return true + case typ.NumOut() == 2 && typ.Out(1) == errorType: + return true + } + return false +} + +// findFunction looks for a function in the template, and global map. +func findFunction(name string, tmpl *Template) (reflect.Value, bool) { + if tmpl != nil && tmpl.common != nil { + if fn := tmpl.execFuncs[name]; fn.IsValid() { + return fn, true + } + } + if fn := builtinFuncs[name]; fn.IsValid() { + return fn, true + } + return reflect.Value{}, false +} + +// Indexing. + +// index returns the result of indexing its first argument by the following +// arguments. Thus "index x 1 2 3" is, in Go syntax, x[1][2][3]. Each +// indexed item must be a map, slice, or array. +func index(item interface{}, indices ...interface{}) (interface{}, error) { + v := reflect.ValueOf(item) + for _, i := range indices { + index := reflect.ValueOf(i) + var isNil bool + if v, isNil = indirect(v); isNil { + return nil, fmt.Errorf("index of nil pointer") + } + switch v.Kind() { + case reflect.Array, reflect.Slice, reflect.String: + var x int64 + switch index.Kind() { + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + x = index.Int() + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + x = int64(index.Uint()) + default: + return nil, fmt.Errorf("cannot index slice/array with type %s", index.Type()) + } + if x < 0 || x >= int64(v.Len()) { + return nil, fmt.Errorf("index out of range: %d", x) + } + v = v.Index(int(x)) + case reflect.Map: + if !index.IsValid() { + index = reflect.Zero(v.Type().Key()) + } + if !index.Type().AssignableTo(v.Type().Key()) { + return nil, fmt.Errorf("%s is not index type for %s", index.Type(), v.Type()) + } + if x := v.MapIndex(index); x.IsValid() { + v = x + } else { + v = reflect.Zero(v.Type().Elem()) + } + default: + return nil, fmt.Errorf("can't index item of type %s", v.Type()) + } + } + return v.Interface(), nil +} + +// Length + +// length returns the length of the item, with an error if it has no defined length. +func length(item interface{}) (int, error) { + v, isNil := indirect(reflect.ValueOf(item)) + if isNil { + return 0, fmt.Errorf("len of nil pointer") + } + switch v.Kind() { + case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice, reflect.String: + return v.Len(), nil + } + return 0, fmt.Errorf("len of type %s", v.Type()) +} + +// Function invocation + +// call returns the result of evaluating the first argument as a function. +// The function must return 1 result, or 2 results, the second of which is an error. +func call(fn interface{}, args ...interface{}) (interface{}, error) { + v := reflect.ValueOf(fn) + typ := v.Type() + if typ.Kind() != reflect.Func { + return nil, fmt.Errorf("non-function of type %s", typ) + } + if !goodFunc(typ) { + return nil, fmt.Errorf("function called with %d args; should be 1 or 2", typ.NumOut()) + } + numIn := typ.NumIn() + var dddType reflect.Type + if typ.IsVariadic() { + if len(args) < numIn-1 { + return nil, fmt.Errorf("wrong number of args: got %d want at least %d", len(args), numIn-1) + } + dddType = typ.In(numIn - 1).Elem() + } else { + if len(args) != numIn { + return nil, fmt.Errorf("wrong number of args: got %d want %d", len(args), numIn) + } + } + argv := make([]reflect.Value, len(args)) + for i, arg := range args { + value := reflect.ValueOf(arg) + // Compute the expected type. Clumsy because of variadics. + var argType reflect.Type + if !typ.IsVariadic() || i < numIn-1 { + argType = typ.In(i) + } else { + argType = dddType + } + if !value.IsValid() && canBeNil(argType) { + value = reflect.Zero(argType) + } + if !value.Type().AssignableTo(argType) { + return nil, fmt.Errorf("arg %d has type %s; should be %s", i, value.Type(), argType) + } + argv[i] = value + } + result := v.Call(argv) + if len(result) == 2 && !result[1].IsNil() { + return result[0].Interface(), result[1].Interface().(error) + } + return result[0].Interface(), nil +} + +// Boolean logic. + +func truth(a interface{}) bool { + t, _ := isTrue(reflect.ValueOf(a)) + return t +} + +// and computes the Boolean AND of its arguments, returning +// the first false argument it encounters, or the last argument. +func and(arg0 interface{}, args ...interface{}) interface{} { + if !truth(arg0) { + return arg0 + } + for i := range args { + arg0 = args[i] + if !truth(arg0) { + break + } + } + return arg0 +} + +// or computes the Boolean OR of its arguments, returning +// the first true argument it encounters, or the last argument. +func or(arg0 interface{}, args ...interface{}) interface{} { + if truth(arg0) { + return arg0 + } + for i := range args { + arg0 = args[i] + if truth(arg0) { + break + } + } + return arg0 +} + +// not returns the Boolean negation of its argument. +func not(arg interface{}) (truth bool) { + truth, _ = isTrue(reflect.ValueOf(arg)) + return !truth +} + +// Comparison. + +// TODO: Perhaps allow comparison between signed and unsigned integers. + +var ( + errBadComparisonType = errors.New("invalid type for comparison") + errBadComparison = errors.New("incompatible types for comparison") + errNoComparison = errors.New("missing argument for comparison") +) + +type kind int + +const ( + invalidKind kind = iota + boolKind + complexKind + intKind + floatKind + integerKind + stringKind + uintKind +) + +func basicKind(v reflect.Value) (kind, error) { + switch v.Kind() { + case reflect.Bool: + return boolKind, nil + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + return intKind, nil + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + return uintKind, nil + case reflect.Float32, reflect.Float64: + return floatKind, nil + case reflect.Complex64, reflect.Complex128: + return complexKind, nil + case reflect.String: + return stringKind, nil + } + return invalidKind, errBadComparisonType +} + +// eq evaluates the comparison a == b || a == c || ... +func eq(arg1 interface{}, arg2 ...interface{}) (bool, error) { + v1 := reflect.ValueOf(arg1) + k1, err := basicKind(v1) + if err != nil { + return false, err + } + if len(arg2) == 0 { + return false, errNoComparison + } + for _, arg := range arg2 { + v2 := reflect.ValueOf(arg) + k2, err := basicKind(v2) + if err != nil { + return false, err + } + if k1 != k2 { + return false, errBadComparison + } + truth := false + switch k1 { + case boolKind: + truth = v1.Bool() == v2.Bool() + case complexKind: + truth = v1.Complex() == v2.Complex() + case floatKind: + truth = v1.Float() == v2.Float() + case intKind: + truth = v1.Int() == v2.Int() + case stringKind: + truth = v1.String() == v2.String() + case uintKind: + truth = v1.Uint() == v2.Uint() + default: + panic("invalid kind") + } + if truth { + return true, nil + } + } + return false, nil +} + +// ne evaluates the comparison a != b. +func ne(arg1, arg2 interface{}) (bool, error) { + // != is the inverse of ==. + equal, err := eq(arg1, arg2) + return !equal, err +} + +// lt evaluates the comparison a < b. +func lt(arg1, arg2 interface{}) (bool, error) { + v1 := reflect.ValueOf(arg1) + k1, err := basicKind(v1) + if err != nil { + return false, err + } + v2 := reflect.ValueOf(arg2) + k2, err := basicKind(v2) + if err != nil { + return false, err + } + if k1 != k2 { + return false, errBadComparison + } + truth := false + switch k1 { + case boolKind, complexKind: + return false, errBadComparisonType + case floatKind: + truth = v1.Float() < v2.Float() + case intKind: + truth = v1.Int() < v2.Int() + case stringKind: + truth = v1.String() < v2.String() + case uintKind: + truth = v1.Uint() < v2.Uint() + default: + panic("invalid kind") + } + return truth, nil +} + +// le evaluates the comparison <= b. +func le(arg1, arg2 interface{}) (bool, error) { + // <= is < or ==. + lessThan, err := lt(arg1, arg2) + if lessThan || err != nil { + return lessThan, err + } + return eq(arg1, arg2) +} + +// gt evaluates the comparison a > b. +func gt(arg1, arg2 interface{}) (bool, error) { + // > is the inverse of <=. + lessOrEqual, err := le(arg1, arg2) + if err != nil { + return false, err + } + return !lessOrEqual, nil +} + +// ge evaluates the comparison a >= b. +func ge(arg1, arg2 interface{}) (bool, error) { + // >= is the inverse of <. + lessThan, err := lt(arg1, arg2) + if err != nil { + return false, err + } + return !lessThan, nil +} + +// HTML escaping. + +var ( + htmlQuot = []byte(""") // shorter than """ + htmlApos = []byte("'") // shorter than "'" and apos was not in HTML until HTML5 + htmlAmp = []byte("&") + htmlLt = []byte("<") + htmlGt = []byte(">") +) + +// HTMLEscape writes to w the escaped HTML equivalent of the plain text data b. +func HTMLEscape(w io.Writer, b []byte) { + last := 0 + for i, c := range b { + var html []byte + switch c { + case '"': + html = htmlQuot + case '\'': + html = htmlApos + case '&': + html = htmlAmp + case '<': + html = htmlLt + case '>': + html = htmlGt + default: + continue + } + w.Write(b[last:i]) + w.Write(html) + last = i + 1 + } + w.Write(b[last:]) +} + +// HTMLEscapeString returns the escaped HTML equivalent of the plain text data s. +func HTMLEscapeString(s string) string { + // Avoid allocation if we can. + if strings.IndexAny(s, `'"&<>`) < 0 { + return s + } + var b bytes.Buffer + HTMLEscape(&b, []byte(s)) + return b.String() +} + +// HTMLEscaper returns the escaped HTML equivalent of the textual +// representation of its arguments. +func HTMLEscaper(args ...interface{}) string { + return HTMLEscapeString(evalArgs(args)) +} + +// JavaScript escaping. + +var ( + jsLowUni = []byte(`\u00`) + hex = []byte("0123456789ABCDEF") + + jsBackslash = []byte(`\\`) + jsApos = []byte(`\'`) + jsQuot = []byte(`\"`) + jsLt = []byte(`\x3C`) + jsGt = []byte(`\x3E`) +) + +// JSEscape writes to w the escaped JavaScript equivalent of the plain text data b. +func JSEscape(w io.Writer, b []byte) { + last := 0 + for i := 0; i < len(b); i++ { + c := b[i] + + if !jsIsSpecial(rune(c)) { + // fast path: nothing to do + continue + } + w.Write(b[last:i]) + + if c < utf8.RuneSelf { + // Quotes, slashes and angle brackets get quoted. + // Control characters get written as \u00XX. + switch c { + case '\\': + w.Write(jsBackslash) + case '\'': + w.Write(jsApos) + case '"': + w.Write(jsQuot) + case '<': + w.Write(jsLt) + case '>': + w.Write(jsGt) + default: + w.Write(jsLowUni) + t, b := c>>4, c&0x0f + w.Write(hex[t : t+1]) + w.Write(hex[b : b+1]) + } + } else { + // Unicode rune. + r, size := utf8.DecodeRune(b[i:]) + if unicode.IsPrint(r) { + w.Write(b[i : i+size]) + } else { + fmt.Fprintf(w, "\\u%04X", r) + } + i += size - 1 + } + last = i + 1 + } + w.Write(b[last:]) +} + +// JSEscapeString returns the escaped JavaScript equivalent of the plain text data s. +func JSEscapeString(s string) string { + // Avoid allocation if we can. + if strings.IndexFunc(s, jsIsSpecial) < 0 { + return s + } + var b bytes.Buffer + JSEscape(&b, []byte(s)) + return b.String() +} + +func jsIsSpecial(r rune) bool { + switch r { + case '\\', '\'', '"', '<', '>': + return true + } + return r < ' ' || utf8.RuneSelf <= r +} + +// JSEscaper returns the escaped JavaScript equivalent of the textual +// representation of its arguments. +func JSEscaper(args ...interface{}) string { + return JSEscapeString(evalArgs(args)) +} + +// URLQueryEscaper returns the escaped value of the textual representation of +// its arguments in a form suitable for embedding in a URL query. +func URLQueryEscaper(args ...interface{}) string { + return url.QueryEscape(evalArgs(args)) +} + +// evalArgs formats the list of arguments into a string. It is therefore equivalent to +// fmt.Sprint(args...) +// except that each argument is indirected (if a pointer), as required, +// using the same rules as the default string evaluation during template +// execution. +func evalArgs(args []interface{}) string { + ok := false + var s string + // Fast path for simple common case. + if len(args) == 1 { + s, ok = args[0].(string) + } + if !ok { + for i, arg := range args { + a, ok := printableValue(reflect.ValueOf(arg)) + if ok { + args[i] = a + } // else left fmt do its thing + } + s = fmt.Sprint(args...) + } + return s +} diff --git a/src/text/template/helper.go b/src/text/template/helper.go new file mode 100644 index 000000000..3636fb54d --- /dev/null +++ b/src/text/template/helper.go @@ -0,0 +1,108 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Helper functions to make constructing templates easier. + +package template + +import ( + "fmt" + "io/ioutil" + "path/filepath" +) + +// Functions and methods to parse templates. + +// Must is a helper that wraps a call to a function returning (*Template, error) +// and panics if the error is non-nil. It is intended for use in variable +// initializations such as +// var t = template.Must(template.New("name").Parse("text")) +func Must(t *Template, err error) *Template { + if err != nil { + panic(err) + } + return t +} + +// ParseFiles creates a new Template and parses the template definitions from +// the named files. The returned template's name will have the (base) name and +// (parsed) contents of the first file. There must be at least one file. +// If an error occurs, parsing stops and the returned *Template is nil. +func ParseFiles(filenames ...string) (*Template, error) { + return parseFiles(nil, filenames...) +} + +// ParseFiles parses the named files and associates the resulting templates with +// t. If an error occurs, parsing stops and the returned template is nil; +// otherwise it is t. There must be at least one file. +func (t *Template) ParseFiles(filenames ...string) (*Template, error) { + return parseFiles(t, filenames...) +} + +// parseFiles is the helper for the method and function. If the argument +// template is nil, it is created from the first file. +func parseFiles(t *Template, filenames ...string) (*Template, error) { + if len(filenames) == 0 { + // Not really a problem, but be consistent. + return nil, fmt.Errorf("template: no files named in call to ParseFiles") + } + for _, filename := range filenames { + b, err := ioutil.ReadFile(filename) + if err != nil { + return nil, err + } + s := string(b) + name := filepath.Base(filename) + // First template becomes return value if not already defined, + // and we use that one for subsequent New calls to associate + // all the templates together. Also, if this file has the same name + // as t, this file becomes the contents of t, so + // t, err := New(name).Funcs(xxx).ParseFiles(name) + // works. Otherwise we create a new template associated with t. + var tmpl *Template + if t == nil { + t = New(name) + } + if name == t.Name() { + tmpl = t + } else { + tmpl = t.New(name) + } + _, err = tmpl.Parse(s) + if err != nil { + return nil, err + } + } + return t, nil +} + +// ParseGlob creates a new Template and parses the template definitions from the +// files identified by the pattern, which must match at least one file. The +// returned template will have the (base) name and (parsed) contents of the +// first file matched by the pattern. ParseGlob is equivalent to calling +// ParseFiles with the list of files matched by the pattern. +func ParseGlob(pattern string) (*Template, error) { + return parseGlob(nil, pattern) +} + +// ParseGlob parses the template definitions in the files identified by the +// pattern and associates the resulting templates with t. The pattern is +// processed by filepath.Glob and must match at least one file. ParseGlob is +// equivalent to calling t.ParseFiles with the list of files matched by the +// pattern. +func (t *Template) ParseGlob(pattern string) (*Template, error) { + return parseGlob(t, pattern) +} + +// parseGlob is the implementation of the function and method ParseGlob. +func parseGlob(t *Template, pattern string) (*Template, error) { + filenames, err := filepath.Glob(pattern) + if err != nil { + return nil, err + } + if len(filenames) == 0 { + return nil, fmt.Errorf("template: pattern matches no files: %#q", pattern) + } + return parseFiles(t, filenames...) +} diff --git a/src/text/template/multi_test.go b/src/text/template/multi_test.go new file mode 100644 index 000000000..e4e804880 --- /dev/null +++ b/src/text/template/multi_test.go @@ -0,0 +1,292 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package template + +// Tests for mulitple-template parsing and execution. + +import ( + "bytes" + "fmt" + "strings" + "testing" + "text/template/parse" +) + +const ( + noError = true + hasError = false +) + +type multiParseTest struct { + name string + input string + ok bool + names []string + results []string +} + +var multiParseTests = []multiParseTest{ + {"empty", "", noError, + nil, + nil}, + {"one", `{{define "foo"}} FOO {{end}}`, noError, + []string{"foo"}, + []string{" FOO "}}, + {"two", `{{define "foo"}} FOO {{end}}{{define "bar"}} BAR {{end}}`, noError, + []string{"foo", "bar"}, + []string{" FOO ", " BAR "}}, + // errors + {"missing end", `{{define "foo"}} FOO `, hasError, + nil, + nil}, + {"malformed name", `{{define "foo}} FOO `, hasError, + nil, + nil}, +} + +func TestMultiParse(t *testing.T) { + for _, test := range multiParseTests { + template, err := New("root").Parse(test.input) + switch { + case err == nil && !test.ok: + t.Errorf("%q: expected error; got none", test.name) + continue + case err != nil && test.ok: + t.Errorf("%q: unexpected error: %v", test.name, err) + continue + case err != nil && !test.ok: + // expected error, got one + if *debug { + fmt.Printf("%s: %s\n\t%s\n", test.name, test.input, err) + } + continue + } + if template == nil { + continue + } + if len(template.tmpl) != len(test.names)+1 { // +1 for root + t.Errorf("%s: wrong number of templates; wanted %d got %d", test.name, len(test.names), len(template.tmpl)) + continue + } + for i, name := range test.names { + tmpl, ok := template.tmpl[name] + if !ok { + t.Errorf("%s: can't find template %q", test.name, name) + continue + } + result := tmpl.Root.String() + if result != test.results[i] { + t.Errorf("%s=(%q): got\n\t%v\nexpected\n\t%v", test.name, test.input, result, test.results[i]) + } + } + } +} + +var multiExecTests = []execTest{ + {"empty", "", "", nil, true}, + {"text", "some text", "some text", nil, true}, + {"invoke x", `{{template "x" .SI}}`, "TEXT", tVal, true}, + {"invoke x no args", `{{template "x"}}`, "TEXT", tVal, true}, + {"invoke dot int", `{{template "dot" .I}}`, "17", tVal, true}, + {"invoke dot []int", `{{template "dot" .SI}}`, "[3 4 5]", tVal, true}, + {"invoke dotV", `{{template "dotV" .U}}`, "v", tVal, true}, + {"invoke nested int", `{{template "nested" .I}}`, "17", tVal, true}, + {"variable declared by template", `{{template "nested" $x:=.SI}},{{index $x 1}}`, "[3 4 5],4", tVal, true}, + + // User-defined function: test argument evaluator. + {"testFunc literal", `{{oneArg "joe"}}`, "oneArg=joe", tVal, true}, + {"testFunc .", `{{oneArg .}}`, "oneArg=joe", "joe", true}, +} + +// These strings are also in testdata/*. +const multiText1 = ` + {{define "x"}}TEXT{{end}} + {{define "dotV"}}{{.V}}{{end}} +` + +const multiText2 = ` + {{define "dot"}}{{.}}{{end}} + {{define "nested"}}{{template "dot" .}}{{end}} +` + +func TestMultiExecute(t *testing.T) { + // Declare a couple of templates first. + template, err := New("root").Parse(multiText1) + if err != nil { + t.Fatalf("parse error for 1: %s", err) + } + _, err = template.Parse(multiText2) + if err != nil { + t.Fatalf("parse error for 2: %s", err) + } + testExecute(multiExecTests, template, t) +} + +func TestParseFiles(t *testing.T) { + _, err := ParseFiles("DOES NOT EXIST") + if err == nil { + t.Error("expected error for non-existent file; got none") + } + template := New("root") + _, err = template.ParseFiles("testdata/file1.tmpl", "testdata/file2.tmpl") + if err != nil { + t.Fatalf("error parsing files: %v", err) + } + testExecute(multiExecTests, template, t) +} + +func TestParseGlob(t *testing.T) { + _, err := ParseGlob("DOES NOT EXIST") + if err == nil { + t.Error("expected error for non-existent file; got none") + } + _, err = New("error").ParseGlob("[x") + if err == nil { + t.Error("expected error for bad pattern; got none") + } + template := New("root") + _, err = template.ParseGlob("testdata/file*.tmpl") + if err != nil { + t.Fatalf("error parsing files: %v", err) + } + testExecute(multiExecTests, template, t) +} + +// In these tests, actual content (not just template definitions) comes from the parsed files. + +var templateFileExecTests = []execTest{ + {"test", `{{template "tmpl1.tmpl"}}{{template "tmpl2.tmpl"}}`, "template1\n\ny\ntemplate2\n\nx\n", 0, true}, +} + +func TestParseFilesWithData(t *testing.T) { + template, err := New("root").ParseFiles("testdata/tmpl1.tmpl", "testdata/tmpl2.tmpl") + if err != nil { + t.Fatalf("error parsing files: %v", err) + } + testExecute(templateFileExecTests, template, t) +} + +func TestParseGlobWithData(t *testing.T) { + template, err := New("root").ParseGlob("testdata/tmpl*.tmpl") + if err != nil { + t.Fatalf("error parsing files: %v", err) + } + testExecute(templateFileExecTests, template, t) +} + +const ( + cloneText1 = `{{define "a"}}{{template "b"}}{{template "c"}}{{end}}` + cloneText2 = `{{define "b"}}b{{end}}` + cloneText3 = `{{define "c"}}root{{end}}` + cloneText4 = `{{define "c"}}clone{{end}}` +) + +func TestClone(t *testing.T) { + // Create some templates and clone the root. + root, err := New("root").Parse(cloneText1) + if err != nil { + t.Fatal(err) + } + _, err = root.Parse(cloneText2) + if err != nil { + t.Fatal(err) + } + clone := Must(root.Clone()) + // Add variants to both. + _, err = root.Parse(cloneText3) + if err != nil { + t.Fatal(err) + } + _, err = clone.Parse(cloneText4) + if err != nil { + t.Fatal(err) + } + // Verify that the clone is self-consistent. + for k, v := range clone.tmpl { + if k == clone.name && v.tmpl[k] != clone { + t.Error("clone does not contain root") + } + if v != v.tmpl[v.name] { + t.Errorf("clone does not contain self for %q", k) + } + } + // Execute root. + var b bytes.Buffer + err = root.ExecuteTemplate(&b, "a", 0) + if err != nil { + t.Fatal(err) + } + if b.String() != "broot" { + t.Errorf("expected %q got %q", "broot", b.String()) + } + // Execute copy. + b.Reset() + err = clone.ExecuteTemplate(&b, "a", 0) + if err != nil { + t.Fatal(err) + } + if b.String() != "bclone" { + t.Errorf("expected %q got %q", "bclone", b.String()) + } +} + +func TestAddParseTree(t *testing.T) { + // Create some templates. + root, err := New("root").Parse(cloneText1) + if err != nil { + t.Fatal(err) + } + _, err = root.Parse(cloneText2) + if err != nil { + t.Fatal(err) + } + // Add a new parse tree. + tree, err := parse.Parse("cloneText3", cloneText3, "", "", nil, builtins) + if err != nil { + t.Fatal(err) + } + added, err := root.AddParseTree("c", tree["c"]) + // Execute. + var b bytes.Buffer + err = added.ExecuteTemplate(&b, "a", 0) + if err != nil { + t.Fatal(err) + } + if b.String() != "broot" { + t.Errorf("expected %q got %q", "broot", b.String()) + } +} + +// Issue 7032 +func TestAddParseTreeToUnparsedTemplate(t *testing.T) { + master := "{{define \"master\"}}{{end}}" + tmpl := New("master") + tree, err := parse.Parse("master", master, "", "", nil) + if err != nil { + t.Fatalf("unexpected parse err: %v", err) + } + masterTree := tree["master"] + tmpl.AddParseTree("master", masterTree) // used to panic +} + +func TestRedefinition(t *testing.T) { + var tmpl *Template + var err error + if tmpl, err = New("tmpl1").Parse(`{{define "test"}}foo{{end}}`); err != nil { + t.Fatalf("parse 1: %v", err) + } + if _, err = tmpl.Parse(`{{define "test"}}bar{{end}}`); err == nil { + t.Fatal("expected error") + } + if !strings.Contains(err.Error(), "redefinition") { + t.Fatalf("expected redefinition error; got %v", err) + } + if _, err = tmpl.New("tmpl2").Parse(`{{define "test"}}bar{{end}}`); err == nil { + t.Fatal("expected error") + } + if !strings.Contains(err.Error(), "redefinition") { + t.Fatalf("expected redefinition error; got %v", err) + } +} diff --git a/src/text/template/parse/lex.go b/src/text/template/parse/lex.go new file mode 100644 index 000000000..1674aaf9c --- /dev/null +++ b/src/text/template/parse/lex.go @@ -0,0 +1,551 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package parse + +import ( + "fmt" + "strings" + "unicode" + "unicode/utf8" +) + +// item represents a token or text string returned from the scanner. +type item struct { + typ itemType // The type of this item. + pos Pos // The starting position, in bytes, of this item in the input string. + val string // The value of this item. +} + +func (i item) String() string { + switch { + case i.typ == itemEOF: + return "EOF" + case i.typ == itemError: + return i.val + case i.typ > itemKeyword: + return fmt.Sprintf("<%s>", i.val) + case len(i.val) > 10: + return fmt.Sprintf("%.10q...", i.val) + } + return fmt.Sprintf("%q", i.val) +} + +// itemType identifies the type of lex items. +type itemType int + +const ( + itemError itemType = iota // error occurred; value is text of error + itemBool // boolean constant + itemChar // printable ASCII character; grab bag for comma etc. + itemCharConstant // character constant + itemComplex // complex constant (1+2i); imaginary is just a number + itemColonEquals // colon-equals (':=') introducing a declaration + itemEOF + itemField // alphanumeric identifier starting with '.' + itemIdentifier // alphanumeric identifier not starting with '.' + itemLeftDelim // left action delimiter + itemLeftParen // '(' inside action + itemNumber // simple number, including imaginary + itemPipe // pipe symbol + itemRawString // raw quoted string (includes quotes) + itemRightDelim // right action delimiter + itemRightParen // ')' inside action + itemSpace // run of spaces separating arguments + itemString // quoted string (includes quotes) + itemText // plain text + itemVariable // variable starting with '$', such as '$' or '$1' or '$hello' + // Keywords appear after all the rest. + itemKeyword // used only to delimit the keywords + itemDot // the cursor, spelled '.' + itemDefine // define keyword + itemElse // else keyword + itemEnd // end keyword + itemIf // if keyword + itemNil // the untyped nil constant, easiest to treat as a keyword + itemRange // range keyword + itemTemplate // template keyword + itemWith // with keyword +) + +var key = map[string]itemType{ + ".": itemDot, + "define": itemDefine, + "else": itemElse, + "end": itemEnd, + "if": itemIf, + "range": itemRange, + "nil": itemNil, + "template": itemTemplate, + "with": itemWith, +} + +const eof = -1 + +// stateFn represents the state of the scanner as a function that returns the next state. +type stateFn func(*lexer) stateFn + +// lexer holds the state of the scanner. +type lexer struct { + name string // the name of the input; used only for error reports + input string // the string being scanned + leftDelim string // start of action + rightDelim string // end of action + state stateFn // the next lexing function to enter + pos Pos // current position in the input + start Pos // start position of this item + width Pos // width of last rune read from input + lastPos Pos // position of most recent item returned by nextItem + items chan item // channel of scanned items + parenDepth int // nesting depth of ( ) exprs +} + +// next returns the next rune in the input. +func (l *lexer) next() rune { + if int(l.pos) >= len(l.input) { + l.width = 0 + return eof + } + r, w := utf8.DecodeRuneInString(l.input[l.pos:]) + l.width = Pos(w) + l.pos += l.width + return r +} + +// peek returns but does not consume the next rune in the input. +func (l *lexer) peek() rune { + r := l.next() + l.backup() + return r +} + +// backup steps back one rune. Can only be called once per call of next. +func (l *lexer) backup() { + l.pos -= l.width +} + +// emit passes an item back to the client. +func (l *lexer) emit(t itemType) { + l.items <- item{t, l.start, l.input[l.start:l.pos]} + l.start = l.pos +} + +// ignore skips over the pending input before this point. +func (l *lexer) ignore() { + l.start = l.pos +} + +// accept consumes the next rune if it's from the valid set. +func (l *lexer) accept(valid string) bool { + if strings.IndexRune(valid, l.next()) >= 0 { + return true + } + l.backup() + return false +} + +// acceptRun consumes a run of runes from the valid set. +func (l *lexer) acceptRun(valid string) { + for strings.IndexRune(valid, l.next()) >= 0 { + } + l.backup() +} + +// lineNumber reports which line we're on, based on the position of +// the previous item returned by nextItem. Doing it this way +// means we don't have to worry about peek double counting. +func (l *lexer) lineNumber() int { + return 1 + strings.Count(l.input[:l.lastPos], "\n") +} + +// errorf returns an error token and terminates the scan by passing +// back a nil pointer that will be the next state, terminating l.nextItem. +func (l *lexer) errorf(format string, args ...interface{}) stateFn { + l.items <- item{itemError, l.start, fmt.Sprintf(format, args...)} + return nil +} + +// nextItem returns the next item from the input. +func (l *lexer) nextItem() item { + item := <-l.items + l.lastPos = item.pos + return item +} + +// lex creates a new scanner for the input string. +func lex(name, input, left, right string) *lexer { + if left == "" { + left = leftDelim + } + if right == "" { + right = rightDelim + } + l := &lexer{ + name: name, + input: input, + leftDelim: left, + rightDelim: right, + items: make(chan item), + } + go l.run() + return l +} + +// run runs the state machine for the lexer. +func (l *lexer) run() { + for l.state = lexText; l.state != nil; { + l.state = l.state(l) + } +} + +// state functions + +const ( + leftDelim = "{{" + rightDelim = "}}" + leftComment = "/*" + rightComment = "*/" +) + +// lexText scans until an opening action delimiter, "{{". +func lexText(l *lexer) stateFn { + for { + if strings.HasPrefix(l.input[l.pos:], l.leftDelim) { + if l.pos > l.start { + l.emit(itemText) + } + return lexLeftDelim + } + if l.next() == eof { + break + } + } + // Correctly reached EOF. + if l.pos > l.start { + l.emit(itemText) + } + l.emit(itemEOF) + return nil +} + +// lexLeftDelim scans the left delimiter, which is known to be present. +func lexLeftDelim(l *lexer) stateFn { + l.pos += Pos(len(l.leftDelim)) + if strings.HasPrefix(l.input[l.pos:], leftComment) { + return lexComment + } + l.emit(itemLeftDelim) + l.parenDepth = 0 + return lexInsideAction +} + +// lexComment scans a comment. The left comment marker is known to be present. +func lexComment(l *lexer) stateFn { + l.pos += Pos(len(leftComment)) + i := strings.Index(l.input[l.pos:], rightComment) + if i < 0 { + return l.errorf("unclosed comment") + } + l.pos += Pos(i + len(rightComment)) + if !strings.HasPrefix(l.input[l.pos:], l.rightDelim) { + return l.errorf("comment ends before closing delimiter") + + } + l.pos += Pos(len(l.rightDelim)) + l.ignore() + return lexText +} + +// lexRightDelim scans the right delimiter, which is known to be present. +func lexRightDelim(l *lexer) stateFn { + l.pos += Pos(len(l.rightDelim)) + l.emit(itemRightDelim) + return lexText +} + +// lexInsideAction scans the elements inside action delimiters. +func lexInsideAction(l *lexer) stateFn { + // Either number, quoted string, or identifier. + // Spaces separate arguments; runs of spaces turn into itemSpace. + // Pipe symbols separate and are emitted. + if strings.HasPrefix(l.input[l.pos:], l.rightDelim) { + if l.parenDepth == 0 { + return lexRightDelim + } + return l.errorf("unclosed left paren") + } + switch r := l.next(); { + case r == eof || isEndOfLine(r): + return l.errorf("unclosed action") + case isSpace(r): + return lexSpace + case r == ':': + if l.next() != '=' { + return l.errorf("expected :=") + } + l.emit(itemColonEquals) + case r == '|': + l.emit(itemPipe) + case r == '"': + return lexQuote + case r == '`': + return lexRawQuote + case r == '$': + return lexVariable + case r == '\'': + return lexChar + case r == '.': + // special look-ahead for ".field" so we don't break l.backup(). + if l.pos < Pos(len(l.input)) { + r := l.input[l.pos] + if r < '0' || '9' < r { + return lexField + } + } + fallthrough // '.' can start a number. + case r == '+' || r == '-' || ('0' <= r && r <= '9'): + l.backup() + return lexNumber + case isAlphaNumeric(r): + l.backup() + return lexIdentifier + case r == '(': + l.emit(itemLeftParen) + l.parenDepth++ + return lexInsideAction + case r == ')': + l.emit(itemRightParen) + l.parenDepth-- + if l.parenDepth < 0 { + return l.errorf("unexpected right paren %#U", r) + } + return lexInsideAction + case r <= unicode.MaxASCII && unicode.IsPrint(r): + l.emit(itemChar) + return lexInsideAction + default: + return l.errorf("unrecognized character in action: %#U", r) + } + return lexInsideAction +} + +// lexSpace scans a run of space characters. +// One space has already been seen. +func lexSpace(l *lexer) stateFn { + for isSpace(l.peek()) { + l.next() + } + l.emit(itemSpace) + return lexInsideAction +} + +// lexIdentifier scans an alphanumeric. +func lexIdentifier(l *lexer) stateFn { +Loop: + for { + switch r := l.next(); { + case isAlphaNumeric(r): + // absorb. + default: + l.backup() + word := l.input[l.start:l.pos] + if !l.atTerminator() { + return l.errorf("bad character %#U", r) + } + switch { + case key[word] > itemKeyword: + l.emit(key[word]) + case word[0] == '.': + l.emit(itemField) + case word == "true", word == "false": + l.emit(itemBool) + default: + l.emit(itemIdentifier) + } + break Loop + } + } + return lexInsideAction +} + +// lexField scans a field: .Alphanumeric. +// The . has been scanned. +func lexField(l *lexer) stateFn { + return lexFieldOrVariable(l, itemField) +} + +// lexVariable scans a Variable: $Alphanumeric. +// The $ has been scanned. +func lexVariable(l *lexer) stateFn { + if l.atTerminator() { // Nothing interesting follows -> "$". + l.emit(itemVariable) + return lexInsideAction + } + return lexFieldOrVariable(l, itemVariable) +} + +// lexVariable scans a field or variable: [.$]Alphanumeric. +// The . or $ has been scanned. +func lexFieldOrVariable(l *lexer, typ itemType) stateFn { + if l.atTerminator() { // Nothing interesting follows -> "." or "$". + if typ == itemVariable { + l.emit(itemVariable) + } else { + l.emit(itemDot) + } + return lexInsideAction + } + var r rune + for { + r = l.next() + if !isAlphaNumeric(r) { + l.backup() + break + } + } + if !l.atTerminator() { + return l.errorf("bad character %#U", r) + } + l.emit(typ) + return lexInsideAction +} + +// atTerminator reports whether the input is at valid termination character to +// appear after an identifier. Breaks .X.Y into two pieces. Also catches cases +// like "$x+2" not being acceptable without a space, in case we decide one +// day to implement arithmetic. +func (l *lexer) atTerminator() bool { + r := l.peek() + if isSpace(r) || isEndOfLine(r) { + return true + } + switch r { + case eof, '.', ',', '|', ':', ')', '(': + return true + } + // Does r start the delimiter? This can be ambiguous (with delim=="//", $x/2 will + // succeed but should fail) but only in extremely rare cases caused by willfully + // bad choice of delimiter. + if rd, _ := utf8.DecodeRuneInString(l.rightDelim); rd == r { + return true + } + return false +} + +// lexChar scans a character constant. The initial quote is already +// scanned. Syntax checking is done by the parser. +func lexChar(l *lexer) stateFn { +Loop: + for { + switch l.next() { + case '\\': + if r := l.next(); r != eof && r != '\n' { + break + } + fallthrough + case eof, '\n': + return l.errorf("unterminated character constant") + case '\'': + break Loop + } + } + l.emit(itemCharConstant) + return lexInsideAction +} + +// lexNumber scans a number: decimal, octal, hex, float, or imaginary. This +// isn't a perfect number scanner - for instance it accepts "." and "0x0.2" +// and "089" - but when it's wrong the input is invalid and the parser (via +// strconv) will notice. +func lexNumber(l *lexer) stateFn { + if !l.scanNumber() { + return l.errorf("bad number syntax: %q", l.input[l.start:l.pos]) + } + if sign := l.peek(); sign == '+' || sign == '-' { + // Complex: 1+2i. No spaces, must end in 'i'. + if !l.scanNumber() || l.input[l.pos-1] != 'i' { + return l.errorf("bad number syntax: %q", l.input[l.start:l.pos]) + } + l.emit(itemComplex) + } else { + l.emit(itemNumber) + } + return lexInsideAction +} + +func (l *lexer) scanNumber() bool { + // Optional leading sign. + l.accept("+-") + // Is it hex? + digits := "0123456789" + if l.accept("0") && l.accept("xX") { + digits = "0123456789abcdefABCDEF" + } + l.acceptRun(digits) + if l.accept(".") { + l.acceptRun(digits) + } + if l.accept("eE") { + l.accept("+-") + l.acceptRun("0123456789") + } + // Is it imaginary? + l.accept("i") + // Next thing mustn't be alphanumeric. + if isAlphaNumeric(l.peek()) { + l.next() + return false + } + return true +} + +// lexQuote scans a quoted string. +func lexQuote(l *lexer) stateFn { +Loop: + for { + switch l.next() { + case '\\': + if r := l.next(); r != eof && r != '\n' { + break + } + fallthrough + case eof, '\n': + return l.errorf("unterminated quoted string") + case '"': + break Loop + } + } + l.emit(itemString) + return lexInsideAction +} + +// lexRawQuote scans a raw quoted string. +func lexRawQuote(l *lexer) stateFn { +Loop: + for { + switch l.next() { + case eof, '\n': + return l.errorf("unterminated raw quoted string") + case '`': + break Loop + } + } + l.emit(itemRawString) + return lexInsideAction +} + +// isSpace reports whether r is a space character. +func isSpace(r rune) bool { + return r == ' ' || r == '\t' +} + +// isEndOfLine reports whether r is an end-of-line character. +func isEndOfLine(r rune) bool { + return r == '\r' || r == '\n' +} + +// isAlphaNumeric reports whether r is an alphabetic, digit, or underscore. +func isAlphaNumeric(r rune) bool { + return r == '_' || unicode.IsLetter(r) || unicode.IsDigit(r) +} diff --git a/src/text/template/parse/lex_test.go b/src/text/template/parse/lex_test.go new file mode 100644 index 000000000..d251ccffb --- /dev/null +++ b/src/text/template/parse/lex_test.go @@ -0,0 +1,465 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package parse + +import ( + "fmt" + "testing" +) + +// Make the types prettyprint. +var itemName = map[itemType]string{ + itemError: "error", + itemBool: "bool", + itemChar: "char", + itemCharConstant: "charconst", + itemComplex: "complex", + itemColonEquals: ":=", + itemEOF: "EOF", + itemField: "field", + itemIdentifier: "identifier", + itemLeftDelim: "left delim", + itemLeftParen: "(", + itemNumber: "number", + itemPipe: "pipe", + itemRawString: "raw string", + itemRightDelim: "right delim", + itemRightParen: ")", + itemSpace: "space", + itemString: "string", + itemVariable: "variable", + + // keywords + itemDot: ".", + itemDefine: "define", + itemElse: "else", + itemIf: "if", + itemEnd: "end", + itemNil: "nil", + itemRange: "range", + itemTemplate: "template", + itemWith: "with", +} + +func (i itemType) String() string { + s := itemName[i] + if s == "" { + return fmt.Sprintf("item%d", int(i)) + } + return s +} + +type lexTest struct { + name string + input string + items []item +} + +var ( + tEOF = item{itemEOF, 0, ""} + tFor = item{itemIdentifier, 0, "for"} + tLeft = item{itemLeftDelim, 0, "{{"} + tLpar = item{itemLeftParen, 0, "("} + tPipe = item{itemPipe, 0, "|"} + tQuote = item{itemString, 0, `"abc \n\t\" "`} + tRange = item{itemRange, 0, "range"} + tRight = item{itemRightDelim, 0, "}}"} + tRpar = item{itemRightParen, 0, ")"} + tSpace = item{itemSpace, 0, " "} + raw = "`" + `abc\n\t\" ` + "`" + tRawQuote = item{itemRawString, 0, raw} +) + +var lexTests = []lexTest{ + {"empty", "", []item{tEOF}}, + {"spaces", " \t\n", []item{{itemText, 0, " \t\n"}, tEOF}}, + {"text", `now is the time`, []item{{itemText, 0, "now is the time"}, tEOF}}, + {"text with comment", "hello-{{/* this is a comment */}}-world", []item{ + {itemText, 0, "hello-"}, + {itemText, 0, "-world"}, + tEOF, + }}, + {"punctuation", "{{,@% }}", []item{ + tLeft, + {itemChar, 0, ","}, + {itemChar, 0, "@"}, + {itemChar, 0, "%"}, + tSpace, + tRight, + tEOF, + }}, + {"parens", "{{((3))}}", []item{ + tLeft, + tLpar, + tLpar, + {itemNumber, 0, "3"}, + tRpar, + tRpar, + tRight, + tEOF, + }}, + {"empty action", `{{}}`, []item{tLeft, tRight, tEOF}}, + {"for", `{{for}}`, []item{tLeft, tFor, tRight, tEOF}}, + {"quote", `{{"abc \n\t\" "}}`, []item{tLeft, tQuote, tRight, tEOF}}, + {"raw quote", "{{" + raw + "}}", []item{tLeft, tRawQuote, tRight, tEOF}}, + {"numbers", "{{1 02 0x14 -7.2i 1e3 +1.2e-4 4.2i 1+2i}}", []item{ + tLeft, + {itemNumber, 0, "1"}, + tSpace, + {itemNumber, 0, "02"}, + tSpace, + {itemNumber, 0, "0x14"}, + tSpace, + {itemNumber, 0, "-7.2i"}, + tSpace, + {itemNumber, 0, "1e3"}, + tSpace, + {itemNumber, 0, "+1.2e-4"}, + tSpace, + {itemNumber, 0, "4.2i"}, + tSpace, + {itemComplex, 0, "1+2i"}, + tRight, + tEOF, + }}, + {"characters", `{{'a' '\n' '\'' '\\' '\u00FF' '\xFF' '本'}}`, []item{ + tLeft, + {itemCharConstant, 0, `'a'`}, + tSpace, + {itemCharConstant, 0, `'\n'`}, + tSpace, + {itemCharConstant, 0, `'\''`}, + tSpace, + {itemCharConstant, 0, `'\\'`}, + tSpace, + {itemCharConstant, 0, `'\u00FF'`}, + tSpace, + {itemCharConstant, 0, `'\xFF'`}, + tSpace, + {itemCharConstant, 0, `'本'`}, + tRight, + tEOF, + }}, + {"bools", "{{true false}}", []item{ + tLeft, + {itemBool, 0, "true"}, + tSpace, + {itemBool, 0, "false"}, + tRight, + tEOF, + }}, + {"dot", "{{.}}", []item{ + tLeft, + {itemDot, 0, "."}, + tRight, + tEOF, + }}, + {"nil", "{{nil}}", []item{ + tLeft, + {itemNil, 0, "nil"}, + tRight, + tEOF, + }}, + {"dots", "{{.x . .2 .x.y.z}}", []item{ + tLeft, + {itemField, 0, ".x"}, + tSpace, + {itemDot, 0, "."}, + tSpace, + {itemNumber, 0, ".2"}, + tSpace, + {itemField, 0, ".x"}, + {itemField, 0, ".y"}, + {itemField, 0, ".z"}, + tRight, + tEOF, + }}, + {"keywords", "{{range if else end with}}", []item{ + tLeft, + {itemRange, 0, "range"}, + tSpace, + {itemIf, 0, "if"}, + tSpace, + {itemElse, 0, "else"}, + tSpace, + {itemEnd, 0, "end"}, + tSpace, + {itemWith, 0, "with"}, + tRight, + tEOF, + }}, + {"variables", "{{$c := printf $ $hello $23 $ $var.Field .Method}}", []item{ + tLeft, + {itemVariable, 0, "$c"}, + tSpace, + {itemColonEquals, 0, ":="}, + tSpace, + {itemIdentifier, 0, "printf"}, + tSpace, + {itemVariable, 0, "$"}, + tSpace, + {itemVariable, 0, "$hello"}, + tSpace, + {itemVariable, 0, "$23"}, + tSpace, + {itemVariable, 0, "$"}, + tSpace, + {itemVariable, 0, "$var"}, + {itemField, 0, ".Field"}, + tSpace, + {itemField, 0, ".Method"}, + tRight, + tEOF, + }}, + {"variable invocation", "{{$x 23}}", []item{ + tLeft, + {itemVariable, 0, "$x"}, + tSpace, + {itemNumber, 0, "23"}, + tRight, + tEOF, + }}, + {"pipeline", `intro {{echo hi 1.2 |noargs|args 1 "hi"}} outro`, []item{ + {itemText, 0, "intro "}, + tLeft, + {itemIdentifier, 0, "echo"}, + tSpace, + {itemIdentifier, 0, "hi"}, + tSpace, + {itemNumber, 0, "1.2"}, + tSpace, + tPipe, + {itemIdentifier, 0, "noargs"}, + tPipe, + {itemIdentifier, 0, "args"}, + tSpace, + {itemNumber, 0, "1"}, + tSpace, + {itemString, 0, `"hi"`}, + tRight, + {itemText, 0, " outro"}, + tEOF, + }}, + {"declaration", "{{$v := 3}}", []item{ + tLeft, + {itemVariable, 0, "$v"}, + tSpace, + {itemColonEquals, 0, ":="}, + tSpace, + {itemNumber, 0, "3"}, + tRight, + tEOF, + }}, + {"2 declarations", "{{$v , $w := 3}}", []item{ + tLeft, + {itemVariable, 0, "$v"}, + tSpace, + {itemChar, 0, ","}, + tSpace, + {itemVariable, 0, "$w"}, + tSpace, + {itemColonEquals, 0, ":="}, + tSpace, + {itemNumber, 0, "3"}, + tRight, + tEOF, + }}, + {"field of parenthesized expression", "{{(.X).Y}}", []item{ + tLeft, + tLpar, + {itemField, 0, ".X"}, + tRpar, + {itemField, 0, ".Y"}, + tRight, + tEOF, + }}, + // errors + {"badchar", "#{{\x01}}", []item{ + {itemText, 0, "#"}, + tLeft, + {itemError, 0, "unrecognized character in action: U+0001"}, + }}, + {"unclosed action", "{{\n}}", []item{ + tLeft, + {itemError, 0, "unclosed action"}, + }}, + {"EOF in action", "{{range", []item{ + tLeft, + tRange, + {itemError, 0, "unclosed action"}, + }}, + {"unclosed quote", "{{\"\n\"}}", []item{ + tLeft, + {itemError, 0, "unterminated quoted string"}, + }}, + {"unclosed raw quote", "{{`xx\n`}}", []item{ + tLeft, + {itemError, 0, "unterminated raw quoted string"}, + }}, + {"unclosed char constant", "{{'\n}}", []item{ + tLeft, + {itemError, 0, "unterminated character constant"}, + }}, + {"bad number", "{{3k}}", []item{ + tLeft, + {itemError, 0, `bad number syntax: "3k"`}, + }}, + {"unclosed paren", "{{(3}}", []item{ + tLeft, + tLpar, + {itemNumber, 0, "3"}, + {itemError, 0, `unclosed left paren`}, + }}, + {"extra right paren", "{{3)}}", []item{ + tLeft, + {itemNumber, 0, "3"}, + tRpar, + {itemError, 0, `unexpected right paren U+0029 ')'`}, + }}, + + // Fixed bugs + // Many elements in an action blew the lookahead until + // we made lexInsideAction not loop. + {"long pipeline deadlock", "{{|||||}}", []item{ + tLeft, + tPipe, + tPipe, + tPipe, + tPipe, + tPipe, + tRight, + tEOF, + }}, + {"text with bad comment", "hello-{{/*/}}-world", []item{ + {itemText, 0, "hello-"}, + {itemError, 0, `unclosed comment`}, + }}, + {"text with comment close separted from delim", "hello-{{/* */ }}-world", []item{ + {itemText, 0, "hello-"}, + {itemError, 0, `comment ends before closing delimiter`}, + }}, + // This one is an error that we can't catch because it breaks templates with + // minimized JavaScript. Should have fixed it before Go 1.1. + {"unmatched right delimiter", "hello-{.}}-world", []item{ + {itemText, 0, "hello-{.}}-world"}, + tEOF, + }}, +} + +// collect gathers the emitted items into a slice. +func collect(t *lexTest, left, right string) (items []item) { + l := lex(t.name, t.input, left, right) + for { + item := l.nextItem() + items = append(items, item) + if item.typ == itemEOF || item.typ == itemError { + break + } + } + return +} + +func equal(i1, i2 []item, checkPos bool) bool { + if len(i1) != len(i2) { + return false + } + for k := range i1 { + if i1[k].typ != i2[k].typ { + return false + } + if i1[k].val != i2[k].val { + return false + } + if checkPos && i1[k].pos != i2[k].pos { + return false + } + } + return true +} + +func TestLex(t *testing.T) { + for _, test := range lexTests { + items := collect(&test, "", "") + if !equal(items, test.items, false) { + t.Errorf("%s: got\n\t%+v\nexpected\n\t%v", test.name, items, test.items) + } + } +} + +// Some easy cases from above, but with delimiters $$ and @@ +var lexDelimTests = []lexTest{ + {"punctuation", "$$,@%{{}}@@", []item{ + tLeftDelim, + {itemChar, 0, ","}, + {itemChar, 0, "@"}, + {itemChar, 0, "%"}, + {itemChar, 0, "{"}, + {itemChar, 0, "{"}, + {itemChar, 0, "}"}, + {itemChar, 0, "}"}, + tRightDelim, + tEOF, + }}, + {"empty action", `$$@@`, []item{tLeftDelim, tRightDelim, tEOF}}, + {"for", `$$for@@`, []item{tLeftDelim, tFor, tRightDelim, tEOF}}, + {"quote", `$$"abc \n\t\" "@@`, []item{tLeftDelim, tQuote, tRightDelim, tEOF}}, + {"raw quote", "$$" + raw + "@@", []item{tLeftDelim, tRawQuote, tRightDelim, tEOF}}, +} + +var ( + tLeftDelim = item{itemLeftDelim, 0, "$$"} + tRightDelim = item{itemRightDelim, 0, "@@"} +) + +func TestDelims(t *testing.T) { + for _, test := range lexDelimTests { + items := collect(&test, "$$", "@@") + if !equal(items, test.items, false) { + t.Errorf("%s: got\n\t%v\nexpected\n\t%v", test.name, items, test.items) + } + } +} + +var lexPosTests = []lexTest{ + {"empty", "", []item{tEOF}}, + {"punctuation", "{{,@%#}}", []item{ + {itemLeftDelim, 0, "{{"}, + {itemChar, 2, ","}, + {itemChar, 3, "@"}, + {itemChar, 4, "%"}, + {itemChar, 5, "#"}, + {itemRightDelim, 6, "}}"}, + {itemEOF, 8, ""}, + }}, + {"sample", "0123{{hello}}xyz", []item{ + {itemText, 0, "0123"}, + {itemLeftDelim, 4, "{{"}, + {itemIdentifier, 6, "hello"}, + {itemRightDelim, 11, "}}"}, + {itemText, 13, "xyz"}, + {itemEOF, 16, ""}, + }}, +} + +// The other tests don't check position, to make the test cases easier to construct. +// This one does. +func TestPos(t *testing.T) { + for _, test := range lexPosTests { + items := collect(&test, "", "") + if !equal(items, test.items, true) { + t.Errorf("%s: got\n\t%v\nexpected\n\t%v", test.name, items, test.items) + if len(items) == len(test.items) { + // Detailed print; avoid item.String() to expose the position value. + for i := range items { + if !equal(items[i:i+1], test.items[i:i+1], true) { + i1 := items[i] + i2 := test.items[i] + t.Errorf("\t#%d: got {%v %d %q} expected {%v %d %q}", i, i1.typ, i1.pos, i1.val, i2.typ, i2.pos, i2.val) + } + } + } + } + } +} diff --git a/src/text/template/parse/node.go b/src/text/template/parse/node.go new file mode 100644 index 000000000..55c37f6db --- /dev/null +++ b/src/text/template/parse/node.go @@ -0,0 +1,834 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Parse nodes. + +package parse + +import ( + "bytes" + "fmt" + "strconv" + "strings" +) + +var textFormat = "%s" // Changed to "%q" in tests for better error messages. + +// A Node is an element in the parse tree. The interface is trivial. +// The interface contains an unexported method so that only +// types local to this package can satisfy it. +type Node interface { + Type() NodeType + String() string + // Copy does a deep copy of the Node and all its components. + // To avoid type assertions, some XxxNodes also have specialized + // CopyXxx methods that return *XxxNode. + Copy() Node + Position() Pos // byte position of start of node in full original input string + // tree returns the containing *Tree. + // It is unexported so all implementations of Node are in this package. + tree() *Tree +} + +// NodeType identifies the type of a parse tree node. +type NodeType int + +// Pos represents a byte position in the original input text from which +// this template was parsed. +type Pos int + +func (p Pos) Position() Pos { + return p +} + +// Type returns itself and provides an easy default implementation +// for embedding in a Node. Embedded in all non-trivial Nodes. +func (t NodeType) Type() NodeType { + return t +} + +const ( + NodeText NodeType = iota // Plain text. + NodeAction // A non-control action such as a field evaluation. + NodeBool // A boolean constant. + NodeChain // A sequence of field accesses. + NodeCommand // An element of a pipeline. + NodeDot // The cursor, dot. + nodeElse // An else action. Not added to tree. + nodeEnd // An end action. Not added to tree. + NodeField // A field or method name. + NodeIdentifier // An identifier; always a function name. + NodeIf // An if action. + NodeList // A list of Nodes. + NodeNil // An untyped nil constant. + NodeNumber // A numerical constant. + NodePipe // A pipeline of commands. + NodeRange // A range action. + NodeString // A string constant. + NodeTemplate // A template invocation action. + NodeVariable // A $ variable. + NodeWith // A with action. +) + +// Nodes. + +// ListNode holds a sequence of nodes. +type ListNode struct { + NodeType + Pos + tr *Tree + Nodes []Node // The element nodes in lexical order. +} + +func (t *Tree) newList(pos Pos) *ListNode { + return &ListNode{tr: t, NodeType: NodeList, Pos: pos} +} + +func (l *ListNode) append(n Node) { + l.Nodes = append(l.Nodes, n) +} + +func (l *ListNode) tree() *Tree { + return l.tr +} + +func (l *ListNode) String() string { + b := new(bytes.Buffer) + for _, n := range l.Nodes { + fmt.Fprint(b, n) + } + return b.String() +} + +func (l *ListNode) CopyList() *ListNode { + if l == nil { + return l + } + n := l.tr.newList(l.Pos) + for _, elem := range l.Nodes { + n.append(elem.Copy()) + } + return n +} + +func (l *ListNode) Copy() Node { + return l.CopyList() +} + +// TextNode holds plain text. +type TextNode struct { + NodeType + Pos + tr *Tree + Text []byte // The text; may span newlines. +} + +func (t *Tree) newText(pos Pos, text string) *TextNode { + return &TextNode{tr: t, NodeType: NodeText, Pos: pos, Text: []byte(text)} +} + +func (t *TextNode) String() string { + return fmt.Sprintf(textFormat, t.Text) +} + +func (t *TextNode) tree() *Tree { + return t.tr +} + +func (t *TextNode) Copy() Node { + return &TextNode{tr: t.tr, NodeType: NodeText, Pos: t.Pos, Text: append([]byte{}, t.Text...)} +} + +// PipeNode holds a pipeline with optional declaration +type PipeNode struct { + NodeType + Pos + tr *Tree + Line int // The line number in the input (deprecated; kept for compatibility) + Decl []*VariableNode // Variable declarations in lexical order. + Cmds []*CommandNode // The commands in lexical order. +} + +func (t *Tree) newPipeline(pos Pos, line int, decl []*VariableNode) *PipeNode { + return &PipeNode{tr: t, NodeType: NodePipe, Pos: pos, Line: line, Decl: decl} +} + +func (p *PipeNode) append(command *CommandNode) { + p.Cmds = append(p.Cmds, command) +} + +func (p *PipeNode) String() string { + s := "" + if len(p.Decl) > 0 { + for i, v := range p.Decl { + if i > 0 { + s += ", " + } + s += v.String() + } + s += " := " + } + for i, c := range p.Cmds { + if i > 0 { + s += " | " + } + s += c.String() + } + return s +} + +func (p *PipeNode) tree() *Tree { + return p.tr +} + +func (p *PipeNode) CopyPipe() *PipeNode { + if p == nil { + return p + } + var decl []*VariableNode + for _, d := range p.Decl { + decl = append(decl, d.Copy().(*VariableNode)) + } + n := p.tr.newPipeline(p.Pos, p.Line, decl) + for _, c := range p.Cmds { + n.append(c.Copy().(*CommandNode)) + } + return n +} + +func (p *PipeNode) Copy() Node { + return p.CopyPipe() +} + +// ActionNode holds an action (something bounded by delimiters). +// Control actions have their own nodes; ActionNode represents simple +// ones such as field evaluations and parenthesized pipelines. +type ActionNode struct { + NodeType + Pos + tr *Tree + Line int // The line number in the input (deprecated; kept for compatibility) + Pipe *PipeNode // The pipeline in the action. +} + +func (t *Tree) newAction(pos Pos, line int, pipe *PipeNode) *ActionNode { + return &ActionNode{tr: t, NodeType: NodeAction, Pos: pos, Line: line, Pipe: pipe} +} + +func (a *ActionNode) String() string { + return fmt.Sprintf("{{%s}}", a.Pipe) + +} + +func (a *ActionNode) tree() *Tree { + return a.tr +} + +func (a *ActionNode) Copy() Node { + return a.tr.newAction(a.Pos, a.Line, a.Pipe.CopyPipe()) + +} + +// CommandNode holds a command (a pipeline inside an evaluating action). +type CommandNode struct { + NodeType + Pos + tr *Tree + Args []Node // Arguments in lexical order: Identifier, field, or constant. +} + +func (t *Tree) newCommand(pos Pos) *CommandNode { + return &CommandNode{tr: t, NodeType: NodeCommand, Pos: pos} +} + +func (c *CommandNode) append(arg Node) { + c.Args = append(c.Args, arg) +} + +func (c *CommandNode) String() string { + s := "" + for i, arg := range c.Args { + if i > 0 { + s += " " + } + if arg, ok := arg.(*PipeNode); ok { + s += "(" + arg.String() + ")" + continue + } + s += arg.String() + } + return s +} + +func (c *CommandNode) tree() *Tree { + return c.tr +} + +func (c *CommandNode) Copy() Node { + if c == nil { + return c + } + n := c.tr.newCommand(c.Pos) + for _, c := range c.Args { + n.append(c.Copy()) + } + return n +} + +// IdentifierNode holds an identifier. +type IdentifierNode struct { + NodeType + Pos + tr *Tree + Ident string // The identifier's name. +} + +// NewIdentifier returns a new IdentifierNode with the given identifier name. +func NewIdentifier(ident string) *IdentifierNode { + return &IdentifierNode{NodeType: NodeIdentifier, Ident: ident} +} + +// SetPos sets the position. NewIdentifier is a public method so we can't modify its signature. +// Chained for convenience. +// TODO: fix one day? +func (i *IdentifierNode) SetPos(pos Pos) *IdentifierNode { + i.Pos = pos + return i +} + +// SetTree sets the parent tree for the node. NewIdentifier is a public method so we can't modify its signature. +// Chained for convenience. +// TODO: fix one day? +func (i *IdentifierNode) SetTree(t *Tree) *IdentifierNode { + i.tr = t + return i +} + +func (i *IdentifierNode) String() string { + return i.Ident +} + +func (i *IdentifierNode) tree() *Tree { + return i.tr +} + +func (i *IdentifierNode) Copy() Node { + return NewIdentifier(i.Ident).SetTree(i.tr).SetPos(i.Pos) +} + +// VariableNode holds a list of variable names, possibly with chained field +// accesses. The dollar sign is part of the (first) name. +type VariableNode struct { + NodeType + Pos + tr *Tree + Ident []string // Variable name and fields in lexical order. +} + +func (t *Tree) newVariable(pos Pos, ident string) *VariableNode { + return &VariableNode{tr: t, NodeType: NodeVariable, Pos: pos, Ident: strings.Split(ident, ".")} +} + +func (v *VariableNode) String() string { + s := "" + for i, id := range v.Ident { + if i > 0 { + s += "." + } + s += id + } + return s +} + +func (v *VariableNode) tree() *Tree { + return v.tr +} + +func (v *VariableNode) Copy() Node { + return &VariableNode{tr: v.tr, NodeType: NodeVariable, Pos: v.Pos, Ident: append([]string{}, v.Ident...)} +} + +// DotNode holds the special identifier '.'. +type DotNode struct { + NodeType + Pos + tr *Tree +} + +func (t *Tree) newDot(pos Pos) *DotNode { + return &DotNode{tr: t, NodeType: NodeDot, Pos: pos} +} + +func (d *DotNode) Type() NodeType { + // Override method on embedded NodeType for API compatibility. + // TODO: Not really a problem; could change API without effect but + // api tool complains. + return NodeDot +} + +func (d *DotNode) String() string { + return "." +} + +func (d *DotNode) tree() *Tree { + return d.tr +} + +func (d *DotNode) Copy() Node { + return d.tr.newDot(d.Pos) +} + +// NilNode holds the special identifier 'nil' representing an untyped nil constant. +type NilNode struct { + NodeType + Pos + tr *Tree +} + +func (t *Tree) newNil(pos Pos) *NilNode { + return &NilNode{tr: t, NodeType: NodeNil, Pos: pos} +} + +func (n *NilNode) Type() NodeType { + // Override method on embedded NodeType for API compatibility. + // TODO: Not really a problem; could change API without effect but + // api tool complains. + return NodeNil +} + +func (n *NilNode) String() string { + return "nil" +} + +func (n *NilNode) tree() *Tree { + return n.tr +} + +func (n *NilNode) Copy() Node { + return n.tr.newNil(n.Pos) +} + +// FieldNode holds a field (identifier starting with '.'). +// The names may be chained ('.x.y'). +// The period is dropped from each ident. +type FieldNode struct { + NodeType + Pos + tr *Tree + Ident []string // The identifiers in lexical order. +} + +func (t *Tree) newField(pos Pos, ident string) *FieldNode { + return &FieldNode{tr: t, NodeType: NodeField, Pos: pos, Ident: strings.Split(ident[1:], ".")} // [1:] to drop leading period +} + +func (f *FieldNode) String() string { + s := "" + for _, id := range f.Ident { + s += "." + id + } + return s +} + +func (f *FieldNode) tree() *Tree { + return f.tr +} + +func (f *FieldNode) Copy() Node { + return &FieldNode{tr: f.tr, NodeType: NodeField, Pos: f.Pos, Ident: append([]string{}, f.Ident...)} +} + +// ChainNode holds a term followed by a chain of field accesses (identifier starting with '.'). +// The names may be chained ('.x.y'). +// The periods are dropped from each ident. +type ChainNode struct { + NodeType + Pos + tr *Tree + Node Node + Field []string // The identifiers in lexical order. +} + +func (t *Tree) newChain(pos Pos, node Node) *ChainNode { + return &ChainNode{tr: t, NodeType: NodeChain, Pos: pos, Node: node} +} + +// Add adds the named field (which should start with a period) to the end of the chain. +func (c *ChainNode) Add(field string) { + if len(field) == 0 || field[0] != '.' { + panic("no dot in field") + } + field = field[1:] // Remove leading dot. + if field == "" { + panic("empty field") + } + c.Field = append(c.Field, field) +} + +func (c *ChainNode) String() string { + s := c.Node.String() + if _, ok := c.Node.(*PipeNode); ok { + s = "(" + s + ")" + } + for _, field := range c.Field { + s += "." + field + } + return s +} + +func (c *ChainNode) tree() *Tree { + return c.tr +} + +func (c *ChainNode) Copy() Node { + return &ChainNode{tr: c.tr, NodeType: NodeChain, Pos: c.Pos, Node: c.Node, Field: append([]string{}, c.Field...)} +} + +// BoolNode holds a boolean constant. +type BoolNode struct { + NodeType + Pos + tr *Tree + True bool // The value of the boolean constant. +} + +func (t *Tree) newBool(pos Pos, true bool) *BoolNode { + return &BoolNode{tr: t, NodeType: NodeBool, Pos: pos, True: true} +} + +func (b *BoolNode) String() string { + if b.True { + return "true" + } + return "false" +} + +func (b *BoolNode) tree() *Tree { + return b.tr +} + +func (b *BoolNode) Copy() Node { + return b.tr.newBool(b.Pos, b.True) +} + +// NumberNode holds a number: signed or unsigned integer, float, or complex. +// The value is parsed and stored under all the types that can represent the value. +// This simulates in a small amount of code the behavior of Go's ideal constants. +type NumberNode struct { + NodeType + Pos + tr *Tree + IsInt bool // Number has an integral value. + IsUint bool // Number has an unsigned integral value. + IsFloat bool // Number has a floating-point value. + IsComplex bool // Number is complex. + Int64 int64 // The signed integer value. + Uint64 uint64 // The unsigned integer value. + Float64 float64 // The floating-point value. + Complex128 complex128 // The complex value. + Text string // The original textual representation from the input. +} + +func (t *Tree) newNumber(pos Pos, text string, typ itemType) (*NumberNode, error) { + n := &NumberNode{tr: t, NodeType: NodeNumber, Pos: pos, Text: text} + switch typ { + case itemCharConstant: + rune, _, tail, err := strconv.UnquoteChar(text[1:], text[0]) + if err != nil { + return nil, err + } + if tail != "'" { + return nil, fmt.Errorf("malformed character constant: %s", text) + } + n.Int64 = int64(rune) + n.IsInt = true + n.Uint64 = uint64(rune) + n.IsUint = true + n.Float64 = float64(rune) // odd but those are the rules. + n.IsFloat = true + return n, nil + case itemComplex: + // fmt.Sscan can parse the pair, so let it do the work. + if _, err := fmt.Sscan(text, &n.Complex128); err != nil { + return nil, err + } + n.IsComplex = true + n.simplifyComplex() + return n, nil + } + // Imaginary constants can only be complex unless they are zero. + if len(text) > 0 && text[len(text)-1] == 'i' { + f, err := strconv.ParseFloat(text[:len(text)-1], 64) + if err == nil { + n.IsComplex = true + n.Complex128 = complex(0, f) + n.simplifyComplex() + return n, nil + } + } + // Do integer test first so we get 0x123 etc. + u, err := strconv.ParseUint(text, 0, 64) // will fail for -0; fixed below. + if err == nil { + n.IsUint = true + n.Uint64 = u + } + i, err := strconv.ParseInt(text, 0, 64) + if err == nil { + n.IsInt = true + n.Int64 = i + if i == 0 { + n.IsUint = true // in case of -0. + n.Uint64 = u + } + } + // If an integer extraction succeeded, promote the float. + if n.IsInt { + n.IsFloat = true + n.Float64 = float64(n.Int64) + } else if n.IsUint { + n.IsFloat = true + n.Float64 = float64(n.Uint64) + } else { + f, err := strconv.ParseFloat(text, 64) + if err == nil { + n.IsFloat = true + n.Float64 = f + // If a floating-point extraction succeeded, extract the int if needed. + if !n.IsInt && float64(int64(f)) == f { + n.IsInt = true + n.Int64 = int64(f) + } + if !n.IsUint && float64(uint64(f)) == f { + n.IsUint = true + n.Uint64 = uint64(f) + } + } + } + if !n.IsInt && !n.IsUint && !n.IsFloat { + return nil, fmt.Errorf("illegal number syntax: %q", text) + } + return n, nil +} + +// simplifyComplex pulls out any other types that are represented by the complex number. +// These all require that the imaginary part be zero. +func (n *NumberNode) simplifyComplex() { + n.IsFloat = imag(n.Complex128) == 0 + if n.IsFloat { + n.Float64 = real(n.Complex128) + n.IsInt = float64(int64(n.Float64)) == n.Float64 + if n.IsInt { + n.Int64 = int64(n.Float64) + } + n.IsUint = float64(uint64(n.Float64)) == n.Float64 + if n.IsUint { + n.Uint64 = uint64(n.Float64) + } + } +} + +func (n *NumberNode) String() string { + return n.Text +} + +func (n *NumberNode) tree() *Tree { + return n.tr +} + +func (n *NumberNode) Copy() Node { + nn := new(NumberNode) + *nn = *n // Easy, fast, correct. + return nn +} + +// StringNode holds a string constant. The value has been "unquoted". +type StringNode struct { + NodeType + Pos + tr *Tree + Quoted string // The original text of the string, with quotes. + Text string // The string, after quote processing. +} + +func (t *Tree) newString(pos Pos, orig, text string) *StringNode { + return &StringNode{tr: t, NodeType: NodeString, Pos: pos, Quoted: orig, Text: text} +} + +func (s *StringNode) String() string { + return s.Quoted +} + +func (s *StringNode) tree() *Tree { + return s.tr +} + +func (s *StringNode) Copy() Node { + return s.tr.newString(s.Pos, s.Quoted, s.Text) +} + +// endNode represents an {{end}} action. +// It does not appear in the final parse tree. +type endNode struct { + NodeType + Pos + tr *Tree +} + +func (t *Tree) newEnd(pos Pos) *endNode { + return &endNode{tr: t, NodeType: nodeEnd, Pos: pos} +} + +func (e *endNode) String() string { + return "{{end}}" +} + +func (e *endNode) tree() *Tree { + return e.tr +} + +func (e *endNode) Copy() Node { + return e.tr.newEnd(e.Pos) +} + +// elseNode represents an {{else}} action. Does not appear in the final tree. +type elseNode struct { + NodeType + Pos + tr *Tree + Line int // The line number in the input (deprecated; kept for compatibility) +} + +func (t *Tree) newElse(pos Pos, line int) *elseNode { + return &elseNode{tr: t, NodeType: nodeElse, Pos: pos, Line: line} +} + +func (e *elseNode) Type() NodeType { + return nodeElse +} + +func (e *elseNode) String() string { + return "{{else}}" +} + +func (e *elseNode) tree() *Tree { + return e.tr +} + +func (e *elseNode) Copy() Node { + return e.tr.newElse(e.Pos, e.Line) +} + +// BranchNode is the common representation of if, range, and with. +type BranchNode struct { + NodeType + Pos + tr *Tree + Line int // The line number in the input (deprecated; kept for compatibility) + Pipe *PipeNode // The pipeline to be evaluated. + List *ListNode // What to execute if the value is non-empty. + ElseList *ListNode // What to execute if the value is empty (nil if absent). +} + +func (b *BranchNode) String() string { + name := "" + switch b.NodeType { + case NodeIf: + name = "if" + case NodeRange: + name = "range" + case NodeWith: + name = "with" + default: + panic("unknown branch type") + } + if b.ElseList != nil { + return fmt.Sprintf("{{%s %s}}%s{{else}}%s{{end}}", name, b.Pipe, b.List, b.ElseList) + } + return fmt.Sprintf("{{%s %s}}%s{{end}}", name, b.Pipe, b.List) +} + +func (b *BranchNode) tree() *Tree { + return b.tr +} + +func (b *BranchNode) Copy() Node { + switch b.NodeType { + case NodeIf: + return b.tr.newIf(b.Pos, b.Line, b.Pipe, b.List, b.ElseList) + case NodeRange: + return b.tr.newRange(b.Pos, b.Line, b.Pipe, b.List, b.ElseList) + case NodeWith: + return b.tr.newWith(b.Pos, b.Line, b.Pipe, b.List, b.ElseList) + default: + panic("unknown branch type") + } +} + +// IfNode represents an {{if}} action and its commands. +type IfNode struct { + BranchNode +} + +func (t *Tree) newIf(pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) *IfNode { + return &IfNode{BranchNode{tr: t, NodeType: NodeIf, Pos: pos, Line: line, Pipe: pipe, List: list, ElseList: elseList}} +} + +func (i *IfNode) Copy() Node { + return i.tr.newIf(i.Pos, i.Line, i.Pipe.CopyPipe(), i.List.CopyList(), i.ElseList.CopyList()) +} + +// RangeNode represents a {{range}} action and its commands. +type RangeNode struct { + BranchNode +} + +func (t *Tree) newRange(pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) *RangeNode { + return &RangeNode{BranchNode{tr: t, NodeType: NodeRange, Pos: pos, Line: line, Pipe: pipe, List: list, ElseList: elseList}} +} + +func (r *RangeNode) Copy() Node { + return r.tr.newRange(r.Pos, r.Line, r.Pipe.CopyPipe(), r.List.CopyList(), r.ElseList.CopyList()) +} + +// WithNode represents a {{with}} action and its commands. +type WithNode struct { + BranchNode +} + +func (t *Tree) newWith(pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) *WithNode { + return &WithNode{BranchNode{tr: t, NodeType: NodeWith, Pos: pos, Line: line, Pipe: pipe, List: list, ElseList: elseList}} +} + +func (w *WithNode) Copy() Node { + return w.tr.newWith(w.Pos, w.Line, w.Pipe.CopyPipe(), w.List.CopyList(), w.ElseList.CopyList()) +} + +// TemplateNode represents a {{template}} action. +type TemplateNode struct { + NodeType + Pos + tr *Tree + Line int // The line number in the input (deprecated; kept for compatibility) + Name string // The name of the template (unquoted). + Pipe *PipeNode // The command to evaluate as dot for the template. +} + +func (t *Tree) newTemplate(pos Pos, line int, name string, pipe *PipeNode) *TemplateNode { + return &TemplateNode{tr: t, NodeType: NodeTemplate, Pos: pos, Line: line, Name: name, Pipe: pipe} +} + +func (t *TemplateNode) String() string { + if t.Pipe == nil { + return fmt.Sprintf("{{template %q}}", t.Name) + } + return fmt.Sprintf("{{template %q %s}}", t.Name, t.Pipe) +} + +func (t *TemplateNode) tree() *Tree { + return t.tr +} + +func (t *TemplateNode) Copy() Node { + return t.tr.newTemplate(t.Pos, t.Line, t.Name, t.Pipe.CopyPipe()) +} diff --git a/src/text/template/parse/parse.go b/src/text/template/parse/parse.go new file mode 100644 index 000000000..af33880c1 --- /dev/null +++ b/src/text/template/parse/parse.go @@ -0,0 +1,677 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package parse builds parse trees for templates as defined by text/template +// and html/template. Clients should use those packages to construct templates +// rather than this one, which provides shared internal data structures not +// intended for general use. +package parse + +import ( + "bytes" + "fmt" + "runtime" + "strconv" + "strings" +) + +// Tree is the representation of a single parsed template. +type Tree struct { + Name string // name of the template represented by the tree. + ParseName string // name of the top-level template during parsing, for error messages. + Root *ListNode // top-level root of the tree. + text string // text parsed to create the template (or its parent) + // Parsing only; cleared after parse. + funcs []map[string]interface{} + lex *lexer + token [3]item // three-token lookahead for parser. + peekCount int + vars []string // variables defined at the moment. +} + +// Copy returns a copy of the Tree. Any parsing state is discarded. +func (t *Tree) Copy() *Tree { + if t == nil { + return nil + } + return &Tree{ + Name: t.Name, + ParseName: t.ParseName, + Root: t.Root.CopyList(), + text: t.text, + } +} + +// Parse returns a map from template name to parse.Tree, created by parsing the +// templates described in the argument string. The top-level template will be +// given the specified name. If an error is encountered, parsing stops and an +// empty map is returned with the error. +func Parse(name, text, leftDelim, rightDelim string, funcs ...map[string]interface{}) (treeSet map[string]*Tree, err error) { + treeSet = make(map[string]*Tree) + t := New(name) + t.text = text + _, err = t.Parse(text, leftDelim, rightDelim, treeSet, funcs...) + return +} + +// next returns the next token. +func (t *Tree) next() item { + if t.peekCount > 0 { + t.peekCount-- + } else { + t.token[0] = t.lex.nextItem() + } + return t.token[t.peekCount] +} + +// backup backs the input stream up one token. +func (t *Tree) backup() { + t.peekCount++ +} + +// backup2 backs the input stream up two tokens. +// The zeroth token is already there. +func (t *Tree) backup2(t1 item) { + t.token[1] = t1 + t.peekCount = 2 +} + +// backup3 backs the input stream up three tokens +// The zeroth token is already there. +func (t *Tree) backup3(t2, t1 item) { // Reverse order: we're pushing back. + t.token[1] = t1 + t.token[2] = t2 + t.peekCount = 3 +} + +// peek returns but does not consume the next token. +func (t *Tree) peek() item { + if t.peekCount > 0 { + return t.token[t.peekCount-1] + } + t.peekCount = 1 + t.token[0] = t.lex.nextItem() + return t.token[0] +} + +// nextNonSpace returns the next non-space token. +func (t *Tree) nextNonSpace() (token item) { + for { + token = t.next() + if token.typ != itemSpace { + break + } + } + return token +} + +// peekNonSpace returns but does not consume the next non-space token. +func (t *Tree) peekNonSpace() (token item) { + for { + token = t.next() + if token.typ != itemSpace { + break + } + } + t.backup() + return token +} + +// Parsing. + +// New allocates a new parse tree with the given name. +func New(name string, funcs ...map[string]interface{}) *Tree { + return &Tree{ + Name: name, + funcs: funcs, + } +} + +// ErrorContext returns a textual representation of the location of the node in the input text. +// The receiver is only used when the node does not have a pointer to the tree inside, +// which can occur in old code. +func (t *Tree) ErrorContext(n Node) (location, context string) { + pos := int(n.Position()) + tree := n.tree() + if tree == nil { + tree = t + } + text := tree.text[:pos] + byteNum := strings.LastIndex(text, "\n") + if byteNum == -1 { + byteNum = pos // On first line. + } else { + byteNum++ // After the newline. + byteNum = pos - byteNum + } + lineNum := 1 + strings.Count(text, "\n") + context = n.String() + if len(context) > 20 { + context = fmt.Sprintf("%.20s...", context) + } + return fmt.Sprintf("%s:%d:%d", tree.ParseName, lineNum, byteNum), context +} + +// errorf formats the error and terminates processing. +func (t *Tree) errorf(format string, args ...interface{}) { + t.Root = nil + format = fmt.Sprintf("template: %s:%d: %s", t.ParseName, t.lex.lineNumber(), format) + panic(fmt.Errorf(format, args...)) +} + +// error terminates processing. +func (t *Tree) error(err error) { + t.errorf("%s", err) +} + +// expect consumes the next token and guarantees it has the required type. +func (t *Tree) expect(expected itemType, context string) item { + token := t.nextNonSpace() + if token.typ != expected { + t.unexpected(token, context) + } + return token +} + +// expectOneOf consumes the next token and guarantees it has one of the required types. +func (t *Tree) expectOneOf(expected1, expected2 itemType, context string) item { + token := t.nextNonSpace() + if token.typ != expected1 && token.typ != expected2 { + t.unexpected(token, context) + } + return token +} + +// unexpected complains about the token and terminates processing. +func (t *Tree) unexpected(token item, context string) { + t.errorf("unexpected %s in %s", token, context) +} + +// recover is the handler that turns panics into returns from the top level of Parse. +func (t *Tree) recover(errp *error) { + e := recover() + if e != nil { + if _, ok := e.(runtime.Error); ok { + panic(e) + } + if t != nil { + t.stopParse() + } + *errp = e.(error) + } + return +} + +// startParse initializes the parser, using the lexer. +func (t *Tree) startParse(funcs []map[string]interface{}, lex *lexer) { + t.Root = nil + t.lex = lex + t.vars = []string{"$"} + t.funcs = funcs +} + +// stopParse terminates parsing. +func (t *Tree) stopParse() { + t.lex = nil + t.vars = nil + t.funcs = nil +} + +// Parse parses the template definition string to construct a representation of +// the template for execution. If either action delimiter string is empty, the +// default ("{{" or "}}") is used. Embedded template definitions are added to +// the treeSet map. +func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]interface{}) (tree *Tree, err error) { + defer t.recover(&err) + t.ParseName = t.Name + t.startParse(funcs, lex(t.Name, text, leftDelim, rightDelim)) + t.text = text + t.parse(treeSet) + t.add(treeSet) + t.stopParse() + return t, nil +} + +// add adds tree to the treeSet. +func (t *Tree) add(treeSet map[string]*Tree) { + tree := treeSet[t.Name] + if tree == nil || IsEmptyTree(tree.Root) { + treeSet[t.Name] = t + return + } + if !IsEmptyTree(t.Root) { + t.errorf("template: multiple definition of template %q", t.Name) + } +} + +// IsEmptyTree reports whether this tree (node) is empty of everything but space. +func IsEmptyTree(n Node) bool { + switch n := n.(type) { + case nil: + return true + case *ActionNode: + case *IfNode: + case *ListNode: + for _, node := range n.Nodes { + if !IsEmptyTree(node) { + return false + } + } + return true + case *RangeNode: + case *TemplateNode: + case *TextNode: + return len(bytes.TrimSpace(n.Text)) == 0 + case *WithNode: + default: + panic("unknown node: " + n.String()) + } + return false +} + +// parse is the top-level parser for a template, essentially the same +// as itemList except it also parses {{define}} actions. +// It runs to EOF. +func (t *Tree) parse(treeSet map[string]*Tree) (next Node) { + t.Root = t.newList(t.peek().pos) + for t.peek().typ != itemEOF { + if t.peek().typ == itemLeftDelim { + delim := t.next() + if t.nextNonSpace().typ == itemDefine { + newT := New("definition") // name will be updated once we know it. + newT.text = t.text + newT.ParseName = t.ParseName + newT.startParse(t.funcs, t.lex) + newT.parseDefinition(treeSet) + continue + } + t.backup2(delim) + } + n := t.textOrAction() + if n.Type() == nodeEnd { + t.errorf("unexpected %s", n) + } + t.Root.append(n) + } + return nil +} + +// parseDefinition parses a {{define}} ... {{end}} template definition and +// installs the definition in the treeSet map. The "define" keyword has already +// been scanned. +func (t *Tree) parseDefinition(treeSet map[string]*Tree) { + const context = "define clause" + name := t.expectOneOf(itemString, itemRawString, context) + var err error + t.Name, err = strconv.Unquote(name.val) + if err != nil { + t.error(err) + } + t.expect(itemRightDelim, context) + var end Node + t.Root, end = t.itemList() + if end.Type() != nodeEnd { + t.errorf("unexpected %s in %s", end, context) + } + t.add(treeSet) + t.stopParse() +} + +// itemList: +// textOrAction* +// Terminates at {{end}} or {{else}}, returned separately. +func (t *Tree) itemList() (list *ListNode, next Node) { + list = t.newList(t.peekNonSpace().pos) + for t.peekNonSpace().typ != itemEOF { + n := t.textOrAction() + switch n.Type() { + case nodeEnd, nodeElse: + return list, n + } + list.append(n) + } + t.errorf("unexpected EOF") + return +} + +// textOrAction: +// text | action +func (t *Tree) textOrAction() Node { + switch token := t.nextNonSpace(); token.typ { + case itemText: + return t.newText(token.pos, token.val) + case itemLeftDelim: + return t.action() + default: + t.unexpected(token, "input") + } + return nil +} + +// Action: +// control +// command ("|" command)* +// Left delim is past. Now get actions. +// First word could be a keyword such as range. +func (t *Tree) action() (n Node) { + switch token := t.nextNonSpace(); token.typ { + case itemElse: + return t.elseControl() + case itemEnd: + return t.endControl() + case itemIf: + return t.ifControl() + case itemRange: + return t.rangeControl() + case itemTemplate: + return t.templateControl() + case itemWith: + return t.withControl() + } + t.backup() + // Do not pop variables; they persist until "end". + return t.newAction(t.peek().pos, t.lex.lineNumber(), t.pipeline("command")) +} + +// Pipeline: +// declarations? command ('|' command)* +func (t *Tree) pipeline(context string) (pipe *PipeNode) { + var decl []*VariableNode + pos := t.peekNonSpace().pos + // Are there declarations? + for { + if v := t.peekNonSpace(); v.typ == itemVariable { + t.next() + // Since space is a token, we need 3-token look-ahead here in the worst case: + // in "$x foo" we need to read "foo" (as opposed to ":=") to know that $x is an + // argument variable rather than a declaration. So remember the token + // adjacent to the variable so we can push it back if necessary. + tokenAfterVariable := t.peek() + if next := t.peekNonSpace(); next.typ == itemColonEquals || (next.typ == itemChar && next.val == ",") { + t.nextNonSpace() + variable := t.newVariable(v.pos, v.val) + decl = append(decl, variable) + t.vars = append(t.vars, v.val) + if next.typ == itemChar && next.val == "," { + if context == "range" && len(decl) < 2 { + continue + } + t.errorf("too many declarations in %s", context) + } + } else if tokenAfterVariable.typ == itemSpace { + t.backup3(v, tokenAfterVariable) + } else { + t.backup2(v) + } + } + break + } + pipe = t.newPipeline(pos, t.lex.lineNumber(), decl) + for { + switch token := t.nextNonSpace(); token.typ { + case itemRightDelim, itemRightParen: + if len(pipe.Cmds) == 0 { + t.errorf("missing value for %s", context) + } + if token.typ == itemRightParen { + t.backup() + } + return + case itemBool, itemCharConstant, itemComplex, itemDot, itemField, itemIdentifier, + itemNumber, itemNil, itemRawString, itemString, itemVariable, itemLeftParen: + t.backup() + pipe.append(t.command()) + default: + t.unexpected(token, context) + } + } +} + +func (t *Tree) parseControl(allowElseIf bool, context string) (pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) { + defer t.popVars(len(t.vars)) + line = t.lex.lineNumber() + pipe = t.pipeline(context) + var next Node + list, next = t.itemList() + switch next.Type() { + case nodeEnd: //done + case nodeElse: + if allowElseIf { + // Special case for "else if". If the "else" is followed immediately by an "if", + // the elseControl will have left the "if" token pending. Treat + // {{if a}}_{{else if b}}_{{end}} + // as + // {{if a}}_{{else}}{{if b}}_{{end}}{{end}}. + // To do this, parse the if as usual and stop at it {{end}}; the subsequent{{end}} + // is assumed. This technique works even for long if-else-if chains. + // TODO: Should we allow else-if in with and range? + if t.peek().typ == itemIf { + t.next() // Consume the "if" token. + elseList = t.newList(next.Position()) + elseList.append(t.ifControl()) + // Do not consume the next item - only one {{end}} required. + break + } + } + elseList, next = t.itemList() + if next.Type() != nodeEnd { + t.errorf("expected end; found %s", next) + } + } + return pipe.Position(), line, pipe, list, elseList +} + +// If: +// {{if pipeline}} itemList {{end}} +// {{if pipeline}} itemList {{else}} itemList {{end}} +// If keyword is past. +func (t *Tree) ifControl() Node { + return t.newIf(t.parseControl(true, "if")) +} + +// Range: +// {{range pipeline}} itemList {{end}} +// {{range pipeline}} itemList {{else}} itemList {{end}} +// Range keyword is past. +func (t *Tree) rangeControl() Node { + return t.newRange(t.parseControl(false, "range")) +} + +// With: +// {{with pipeline}} itemList {{end}} +// {{with pipeline}} itemList {{else}} itemList {{end}} +// If keyword is past. +func (t *Tree) withControl() Node { + return t.newWith(t.parseControl(false, "with")) +} + +// End: +// {{end}} +// End keyword is past. +func (t *Tree) endControl() Node { + return t.newEnd(t.expect(itemRightDelim, "end").pos) +} + +// Else: +// {{else}} +// Else keyword is past. +func (t *Tree) elseControl() Node { + // Special case for "else if". + peek := t.peekNonSpace() + if peek.typ == itemIf { + // We see "{{else if ... " but in effect rewrite it to {{else}}{{if ... ". + return t.newElse(peek.pos, t.lex.lineNumber()) + } + return t.newElse(t.expect(itemRightDelim, "else").pos, t.lex.lineNumber()) +} + +// Template: +// {{template stringValue pipeline}} +// Template keyword is past. The name must be something that can evaluate +// to a string. +func (t *Tree) templateControl() Node { + var name string + token := t.nextNonSpace() + switch token.typ { + case itemString, itemRawString: + s, err := strconv.Unquote(token.val) + if err != nil { + t.error(err) + } + name = s + default: + t.unexpected(token, "template invocation") + } + var pipe *PipeNode + if t.nextNonSpace().typ != itemRightDelim { + t.backup() + // Do not pop variables; they persist until "end". + pipe = t.pipeline("template") + } + return t.newTemplate(token.pos, t.lex.lineNumber(), name, pipe) +} + +// command: +// operand (space operand)* +// space-separated arguments up to a pipeline character or right delimiter. +// we consume the pipe character but leave the right delim to terminate the action. +func (t *Tree) command() *CommandNode { + cmd := t.newCommand(t.peekNonSpace().pos) + for { + t.peekNonSpace() // skip leading spaces. + operand := t.operand() + if operand != nil { + cmd.append(operand) + } + switch token := t.next(); token.typ { + case itemSpace: + continue + case itemError: + t.errorf("%s", token.val) + case itemRightDelim, itemRightParen: + t.backup() + case itemPipe: + default: + t.errorf("unexpected %s in operand; missing space?", token) + } + break + } + if len(cmd.Args) == 0 { + t.errorf("empty command") + } + return cmd +} + +// operand: +// term .Field* +// An operand is a space-separated component of a command, +// a term possibly followed by field accesses. +// A nil return means the next item is not an operand. +func (t *Tree) operand() Node { + node := t.term() + if node == nil { + return nil + } + if t.peek().typ == itemField { + chain := t.newChain(t.peek().pos, node) + for t.peek().typ == itemField { + chain.Add(t.next().val) + } + // Compatibility with original API: If the term is of type NodeField + // or NodeVariable, just put more fields on the original. + // Otherwise, keep the Chain node. + // TODO: Switch to Chains always when we can. + switch node.Type() { + case NodeField: + node = t.newField(chain.Position(), chain.String()) + case NodeVariable: + node = t.newVariable(chain.Position(), chain.String()) + default: + node = chain + } + } + return node +} + +// term: +// literal (number, string, nil, boolean) +// function (identifier) +// . +// .Field +// $ +// '(' pipeline ')' +// A term is a simple "expression". +// A nil return means the next item is not a term. +func (t *Tree) term() Node { + switch token := t.nextNonSpace(); token.typ { + case itemError: + t.errorf("%s", token.val) + case itemIdentifier: + if !t.hasFunction(token.val) { + t.errorf("function %q not defined", token.val) + } + return NewIdentifier(token.val).SetTree(t).SetPos(token.pos) + case itemDot: + return t.newDot(token.pos) + case itemNil: + return t.newNil(token.pos) + case itemVariable: + return t.useVar(token.pos, token.val) + case itemField: + return t.newField(token.pos, token.val) + case itemBool: + return t.newBool(token.pos, token.val == "true") + case itemCharConstant, itemComplex, itemNumber: + number, err := t.newNumber(token.pos, token.val, token.typ) + if err != nil { + t.error(err) + } + return number + case itemLeftParen: + pipe := t.pipeline("parenthesized pipeline") + if token := t.next(); token.typ != itemRightParen { + t.errorf("unclosed right paren: unexpected %s", token) + } + return pipe + case itemString, itemRawString: + s, err := strconv.Unquote(token.val) + if err != nil { + t.error(err) + } + return t.newString(token.pos, token.val, s) + } + t.backup() + return nil +} + +// hasFunction reports if a function name exists in the Tree's maps. +func (t *Tree) hasFunction(name string) bool { + for _, funcMap := range t.funcs { + if funcMap == nil { + continue + } + if funcMap[name] != nil { + return true + } + } + return false +} + +// popVars trims the variable list to the specified length +func (t *Tree) popVars(n int) { + t.vars = t.vars[:n] +} + +// useVar returns a node for a variable reference. It errors if the +// variable is not defined. +func (t *Tree) useVar(pos Pos, name string) Node { + v := t.newVariable(pos, name) + for _, varName := range t.vars { + if varName == v.Ident[0] { + return v + } + } + t.errorf("undefined variable %q", v.Ident[0]) + return nil +} diff --git a/src/text/template/parse/parse_test.go b/src/text/template/parse/parse_test.go new file mode 100644 index 000000000..4a504fa7c --- /dev/null +++ b/src/text/template/parse/parse_test.go @@ -0,0 +1,423 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package parse + +import ( + "flag" + "fmt" + "strings" + "testing" +) + +var debug = flag.Bool("debug", false, "show the errors produced by the main tests") + +type numberTest struct { + text string + isInt bool + isUint bool + isFloat bool + isComplex bool + int64 + uint64 + float64 + complex128 +} + +var numberTests = []numberTest{ + // basics + {"0", true, true, true, false, 0, 0, 0, 0}, + {"-0", true, true, true, false, 0, 0, 0, 0}, // check that -0 is a uint. + {"73", true, true, true, false, 73, 73, 73, 0}, + {"073", true, true, true, false, 073, 073, 073, 0}, + {"0x73", true, true, true, false, 0x73, 0x73, 0x73, 0}, + {"-73", true, false, true, false, -73, 0, -73, 0}, + {"+73", true, false, true, false, 73, 0, 73, 0}, + {"100", true, true, true, false, 100, 100, 100, 0}, + {"1e9", true, true, true, false, 1e9, 1e9, 1e9, 0}, + {"-1e9", true, false, true, false, -1e9, 0, -1e9, 0}, + {"-1.2", false, false, true, false, 0, 0, -1.2, 0}, + {"1e19", false, true, true, false, 0, 1e19, 1e19, 0}, + {"-1e19", false, false, true, false, 0, 0, -1e19, 0}, + {"4i", false, false, false, true, 0, 0, 0, 4i}, + {"-1.2+4.2i", false, false, false, true, 0, 0, 0, -1.2 + 4.2i}, + {"073i", false, false, false, true, 0, 0, 0, 73i}, // not octal! + // complex with 0 imaginary are float (and maybe integer) + {"0i", true, true, true, true, 0, 0, 0, 0}, + {"-1.2+0i", false, false, true, true, 0, 0, -1.2, -1.2}, + {"-12+0i", true, false, true, true, -12, 0, -12, -12}, + {"13+0i", true, true, true, true, 13, 13, 13, 13}, + // funny bases + {"0123", true, true, true, false, 0123, 0123, 0123, 0}, + {"-0x0", true, true, true, false, 0, 0, 0, 0}, + {"0xdeadbeef", true, true, true, false, 0xdeadbeef, 0xdeadbeef, 0xdeadbeef, 0}, + // character constants + {`'a'`, true, true, true, false, 'a', 'a', 'a', 0}, + {`'\n'`, true, true, true, false, '\n', '\n', '\n', 0}, + {`'\\'`, true, true, true, false, '\\', '\\', '\\', 0}, + {`'\''`, true, true, true, false, '\'', '\'', '\'', 0}, + {`'\xFF'`, true, true, true, false, 0xFF, 0xFF, 0xFF, 0}, + {`'パ'`, true, true, true, false, 0x30d1, 0x30d1, 0x30d1, 0}, + {`'\u30d1'`, true, true, true, false, 0x30d1, 0x30d1, 0x30d1, 0}, + {`'\U000030d1'`, true, true, true, false, 0x30d1, 0x30d1, 0x30d1, 0}, + // some broken syntax + {text: "+-2"}, + {text: "0x123."}, + {text: "1e."}, + {text: "0xi."}, + {text: "1+2."}, + {text: "'x"}, + {text: "'xx'"}, + // Issue 8622 - 0xe parsed as floating point. Very embarrassing. + {"0xef", true, true, true, false, 0xef, 0xef, 0xef, 0}, +} + +func TestNumberParse(t *testing.T) { + for _, test := range numberTests { + // If fmt.Sscan thinks it's complex, it's complex. We can't trust the output + // because imaginary comes out as a number. + var c complex128 + typ := itemNumber + var tree *Tree + if test.text[0] == '\'' { + typ = itemCharConstant + } else { + _, err := fmt.Sscan(test.text, &c) + if err == nil { + typ = itemComplex + } + } + n, err := tree.newNumber(0, test.text, typ) + ok := test.isInt || test.isUint || test.isFloat || test.isComplex + if ok && err != nil { + t.Errorf("unexpected error for %q: %s", test.text, err) + continue + } + if !ok && err == nil { + t.Errorf("expected error for %q", test.text) + continue + } + if !ok { + if *debug { + fmt.Printf("%s\n\t%s\n", test.text, err) + } + continue + } + if n.IsComplex != test.isComplex { + t.Errorf("complex incorrect for %q; should be %t", test.text, test.isComplex) + } + if test.isInt { + if !n.IsInt { + t.Errorf("expected integer for %q", test.text) + } + if n.Int64 != test.int64 { + t.Errorf("int64 for %q should be %d Is %d", test.text, test.int64, n.Int64) + } + } else if n.IsInt { + t.Errorf("did not expect integer for %q", test.text) + } + if test.isUint { + if !n.IsUint { + t.Errorf("expected unsigned integer for %q", test.text) + } + if n.Uint64 != test.uint64 { + t.Errorf("uint64 for %q should be %d Is %d", test.text, test.uint64, n.Uint64) + } + } else if n.IsUint { + t.Errorf("did not expect unsigned integer for %q", test.text) + } + if test.isFloat { + if !n.IsFloat { + t.Errorf("expected float for %q", test.text) + } + if n.Float64 != test.float64 { + t.Errorf("float64 for %q should be %g Is %g", test.text, test.float64, n.Float64) + } + } else if n.IsFloat { + t.Errorf("did not expect float for %q", test.text) + } + if test.isComplex { + if !n.IsComplex { + t.Errorf("expected complex for %q", test.text) + } + if n.Complex128 != test.complex128 { + t.Errorf("complex128 for %q should be %g Is %g", test.text, test.complex128, n.Complex128) + } + } else if n.IsComplex { + t.Errorf("did not expect complex for %q", test.text) + } + } +} + +type parseTest struct { + name string + input string + ok bool + result string // what the user would see in an error message. +} + +const ( + noError = true + hasError = false +) + +var parseTests = []parseTest{ + {"empty", "", noError, + ``}, + {"comment", "{{/*\n\n\n*/}}", noError, + ``}, + {"spaces", " \t\n", noError, + `" \t\n"`}, + {"text", "some text", noError, + `"some text"`}, + {"emptyAction", "{{}}", hasError, + `{{}}`}, + {"field", "{{.X}}", noError, + `{{.X}}`}, + {"simple command", "{{printf}}", noError, + `{{printf}}`}, + {"$ invocation", "{{$}}", noError, + "{{$}}"}, + {"variable invocation", "{{with $x := 3}}{{$x 23}}{{end}}", noError, + "{{with $x := 3}}{{$x 23}}{{end}}"}, + {"variable with fields", "{{$.I}}", noError, + "{{$.I}}"}, + {"multi-word command", "{{printf `%d` 23}}", noError, + "{{printf `%d` 23}}"}, + {"pipeline", "{{.X|.Y}}", noError, + `{{.X | .Y}}`}, + {"pipeline with decl", "{{$x := .X|.Y}}", noError, + `{{$x := .X | .Y}}`}, + {"nested pipeline", "{{.X (.Y .Z) (.A | .B .C) (.E)}}", noError, + `{{.X (.Y .Z) (.A | .B .C) (.E)}}`}, + {"field applied to parentheses", "{{(.Y .Z).Field}}", noError, + `{{(.Y .Z).Field}}`}, + {"simple if", "{{if .X}}hello{{end}}", noError, + `{{if .X}}"hello"{{end}}`}, + {"if with else", "{{if .X}}true{{else}}false{{end}}", noError, + `{{if .X}}"true"{{else}}"false"{{end}}`}, + {"if with else if", "{{if .X}}true{{else if .Y}}false{{end}}", noError, + `{{if .X}}"true"{{else}}{{if .Y}}"false"{{end}}{{end}}`}, + {"if else chain", "+{{if .X}}X{{else if .Y}}Y{{else if .Z}}Z{{end}}+", noError, + `"+"{{if .X}}"X"{{else}}{{if .Y}}"Y"{{else}}{{if .Z}}"Z"{{end}}{{end}}{{end}}"+"`}, + {"simple range", "{{range .X}}hello{{end}}", noError, + `{{range .X}}"hello"{{end}}`}, + {"chained field range", "{{range .X.Y.Z}}hello{{end}}", noError, + `{{range .X.Y.Z}}"hello"{{end}}`}, + {"nested range", "{{range .X}}hello{{range .Y}}goodbye{{end}}{{end}}", noError, + `{{range .X}}"hello"{{range .Y}}"goodbye"{{end}}{{end}}`}, + {"range with else", "{{range .X}}true{{else}}false{{end}}", noError, + `{{range .X}}"true"{{else}}"false"{{end}}`}, + {"range over pipeline", "{{range .X|.M}}true{{else}}false{{end}}", noError, + `{{range .X | .M}}"true"{{else}}"false"{{end}}`}, + {"range []int", "{{range .SI}}{{.}}{{end}}", noError, + `{{range .SI}}{{.}}{{end}}`}, + {"range 1 var", "{{range $x := .SI}}{{.}}{{end}}", noError, + `{{range $x := .SI}}{{.}}{{end}}`}, + {"range 2 vars", "{{range $x, $y := .SI}}{{.}}{{end}}", noError, + `{{range $x, $y := .SI}}{{.}}{{end}}`}, + {"constants", "{{range .SI 1 -3.2i true false 'a' nil}}{{end}}", noError, + `{{range .SI 1 -3.2i true false 'a' nil}}{{end}}`}, + {"template", "{{template `x`}}", noError, + `{{template "x"}}`}, + {"template with arg", "{{template `x` .Y}}", noError, + `{{template "x" .Y}}`}, + {"with", "{{with .X}}hello{{end}}", noError, + `{{with .X}}"hello"{{end}}`}, + {"with with else", "{{with .X}}hello{{else}}goodbye{{end}}", noError, + `{{with .X}}"hello"{{else}}"goodbye"{{end}}`}, + // Errors. + {"unclosed action", "hello{{range", hasError, ""}, + {"unmatched end", "{{end}}", hasError, ""}, + {"missing end", "hello{{range .x}}", hasError, ""}, + {"missing end after else", "hello{{range .x}}{{else}}", hasError, ""}, + {"undefined function", "hello{{undefined}}", hasError, ""}, + {"undefined variable", "{{$x}}", hasError, ""}, + {"variable undefined after end", "{{with $x := 4}}{{end}}{{$x}}", hasError, ""}, + {"variable undefined in template", "{{template $v}}", hasError, ""}, + {"declare with field", "{{with $x.Y := 4}}{{end}}", hasError, ""}, + {"template with field ref", "{{template .X}}", hasError, ""}, + {"template with var", "{{template $v}}", hasError, ""}, + {"invalid punctuation", "{{printf 3, 4}}", hasError, ""}, + {"multidecl outside range", "{{with $v, $u := 3}}{{end}}", hasError, ""}, + {"too many decls in range", "{{range $u, $v, $w := 3}}{{end}}", hasError, ""}, + {"dot applied to parentheses", "{{printf (printf .).}}", hasError, ""}, + {"adjacent args", "{{printf 3`x`}}", hasError, ""}, + {"adjacent args with .", "{{printf `x`.}}", hasError, ""}, + {"extra end after if", "{{if .X}}a{{else if .Y}}b{{end}}{{end}}", hasError, ""}, + // Equals (and other chars) do not assignments make (yet). + {"bug0a", "{{$x := 0}}{{$x}}", noError, "{{$x := 0}}{{$x}}"}, + {"bug0b", "{{$x = 1}}{{$x}}", hasError, ""}, + {"bug0c", "{{$x ! 2}}{{$x}}", hasError, ""}, + {"bug0d", "{{$x % 3}}{{$x}}", hasError, ""}, + // Check the parse fails for := rather than comma. + {"bug0e", "{{range $x := $y := 3}}{{end}}", hasError, ""}, + // Another bug: variable read must ignore following punctuation. + {"bug1a", "{{$x:=.}}{{$x!2}}", hasError, ""}, // ! is just illegal here. + {"bug1b", "{{$x:=.}}{{$x+2}}", hasError, ""}, // $x+2 should not parse as ($x) (+2). + {"bug1c", "{{$x:=.}}{{$x +2}}", noError, "{{$x := .}}{{$x +2}}"}, // It's OK with a space. +} + +var builtins = map[string]interface{}{ + "printf": fmt.Sprintf, +} + +func testParse(doCopy bool, t *testing.T) { + textFormat = "%q" + defer func() { textFormat = "%s" }() + for _, test := range parseTests { + tmpl, err := New(test.name).Parse(test.input, "", "", make(map[string]*Tree), builtins) + switch { + case err == nil && !test.ok: + t.Errorf("%q: expected error; got none", test.name) + continue + case err != nil && test.ok: + t.Errorf("%q: unexpected error: %v", test.name, err) + continue + case err != nil && !test.ok: + // expected error, got one + if *debug { + fmt.Printf("%s: %s\n\t%s\n", test.name, test.input, err) + } + continue + } + var result string + if doCopy { + result = tmpl.Root.Copy().String() + } else { + result = tmpl.Root.String() + } + if result != test.result { + t.Errorf("%s=(%q): got\n\t%v\nexpected\n\t%v", test.name, test.input, result, test.result) + } + } +} + +func TestParse(t *testing.T) { + testParse(false, t) +} + +// Same as TestParse, but we copy the node first +func TestParseCopy(t *testing.T) { + testParse(true, t) +} + +type isEmptyTest struct { + name string + input string + empty bool +} + +var isEmptyTests = []isEmptyTest{ + {"empty", ``, true}, + {"nonempty", `hello`, false}, + {"spaces only", " \t\n \t\n", true}, + {"definition", `{{define "x"}}something{{end}}`, true}, + {"definitions and space", "{{define `x`}}something{{end}}\n\n{{define `y`}}something{{end}}\n\n", true}, + {"definitions and text", "{{define `x`}}something{{end}}\nx\n{{define `y`}}something{{end}}\ny\n", false}, + {"definition and action", "{{define `x`}}something{{end}}{{if 3}}foo{{end}}", false}, +} + +func TestIsEmpty(t *testing.T) { + if !IsEmptyTree(nil) { + t.Errorf("nil tree is not empty") + } + for _, test := range isEmptyTests { + tree, err := New("root").Parse(test.input, "", "", make(map[string]*Tree), nil) + if err != nil { + t.Errorf("%q: unexpected error: %v", test.name, err) + continue + } + if empty := IsEmptyTree(tree.Root); empty != test.empty { + t.Errorf("%q: expected %t got %t", test.name, test.empty, empty) + } + } +} + +func TestErrorContextWithTreeCopy(t *testing.T) { + tree, err := New("root").Parse("{{if true}}{{end}}", "", "", make(map[string]*Tree), nil) + if err != nil { + t.Fatalf("unexpected tree parse failure: %v", err) + } + treeCopy := tree.Copy() + wantLocation, wantContext := tree.ErrorContext(tree.Root.Nodes[0]) + gotLocation, gotContext := treeCopy.ErrorContext(treeCopy.Root.Nodes[0]) + if wantLocation != gotLocation { + t.Errorf("wrong error location want %q got %q", wantLocation, gotLocation) + } + if wantContext != gotContext { + t.Errorf("wrong error location want %q got %q", wantContext, gotContext) + } +} + +// All failures, and the result is a string that must appear in the error message. +var errorTests = []parseTest{ + // Check line numbers are accurate. + {"unclosed1", + "line1\n{{", + hasError, `unclosed1:2: unexpected unclosed action in command`}, + {"unclosed2", + "line1\n{{define `x`}}line2\n{{", + hasError, `unclosed2:3: unexpected unclosed action in command`}, + // Specific errors. + {"function", + "{{foo}}", + hasError, `function "foo" not defined`}, + {"comment", + "{{/*}}", + hasError, `unclosed comment`}, + {"lparen", + "{{.X (1 2 3}}", + hasError, `unclosed left paren`}, + {"rparen", + "{{.X 1 2 3)}}", + hasError, `unexpected ")"`}, + {"space", + "{{`x`3}}", + hasError, `missing space?`}, + {"idchar", + "{{a#}}", + hasError, `'#'`}, + {"charconst", + "{{'a}}", + hasError, `unterminated character constant`}, + {"stringconst", + `{{"a}}`, + hasError, `unterminated quoted string`}, + {"rawstringconst", + "{{`a}}", + hasError, `unterminated raw quoted string`}, + {"number", + "{{0xi}}", + hasError, `number syntax`}, + {"multidefine", + "{{define `a`}}a{{end}}{{define `a`}}b{{end}}", + hasError, `multiple definition of template`}, + {"eof", + "{{range .X}}", + hasError, `unexpected EOF`}, + {"variable", + // Declare $x so it's defined, to avoid that error, and then check we don't parse a declaration. + "{{$x := 23}}{{with $x.y := 3}}{{$x 23}}{{end}}", + hasError, `unexpected ":="`}, + {"multidecl", + "{{$a,$b,$c := 23}}", + hasError, `too many declarations`}, + {"undefvar", + "{{$a}}", + hasError, `undefined variable`}, +} + +func TestErrors(t *testing.T) { + for _, test := range errorTests { + _, err := New(test.name).Parse(test.input, "", "", make(map[string]*Tree)) + if err == nil { + t.Errorf("%q: expected error", test.name) + continue + } + if !strings.Contains(err.Error(), test.result) { + t.Errorf("%q: error %q does not contain %q", test.name, err, test.result) + } + } +} diff --git a/src/text/template/template.go b/src/text/template/template.go new file mode 100644 index 000000000..249d0cbfb --- /dev/null +++ b/src/text/template/template.go @@ -0,0 +1,217 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package template + +import ( + "fmt" + "reflect" + "text/template/parse" +) + +// common holds the information shared by related templates. +type common struct { + tmpl map[string]*Template + // We use two maps, one for parsing and one for execution. + // This separation makes the API cleaner since it doesn't + // expose reflection to the client. + parseFuncs FuncMap + execFuncs map[string]reflect.Value +} + +// Template is the representation of a parsed template. The *parse.Tree +// field is exported only for use by html/template and should be treated +// as unexported by all other clients. +type Template struct { + name string + *parse.Tree + *common + leftDelim string + rightDelim string +} + +// New allocates a new template with the given name. +func New(name string) *Template { + return &Template{ + name: name, + } +} + +// Name returns the name of the template. +func (t *Template) Name() string { + return t.name +} + +// New allocates a new template associated with the given one and with the same +// delimiters. The association, which is transitive, allows one template to +// invoke another with a {{template}} action. +func (t *Template) New(name string) *Template { + t.init() + return &Template{ + name: name, + common: t.common, + leftDelim: t.leftDelim, + rightDelim: t.rightDelim, + } +} + +func (t *Template) init() { + if t.common == nil { + t.common = new(common) + t.tmpl = make(map[string]*Template) + t.parseFuncs = make(FuncMap) + t.execFuncs = make(map[string]reflect.Value) + } +} + +// Clone returns a duplicate of the template, including all associated +// templates. The actual representation is not copied, but the name space of +// associated templates is, so further calls to Parse in the copy will add +// templates to the copy but not to the original. Clone can be used to prepare +// common templates and use them with variant definitions for other templates +// by adding the variants after the clone is made. +func (t *Template) Clone() (*Template, error) { + nt := t.copy(nil) + nt.init() + nt.tmpl[t.name] = nt + for k, v := range t.tmpl { + if k == t.name { // Already installed. + continue + } + // The associated templates share nt's common structure. + tmpl := v.copy(nt.common) + nt.tmpl[k] = tmpl + } + for k, v := range t.parseFuncs { + nt.parseFuncs[k] = v + } + for k, v := range t.execFuncs { + nt.execFuncs[k] = v + } + return nt, nil +} + +// copy returns a shallow copy of t, with common set to the argument. +func (t *Template) copy(c *common) *Template { + nt := New(t.name) + nt.Tree = t.Tree + nt.common = c + nt.leftDelim = t.leftDelim + nt.rightDelim = t.rightDelim + return nt +} + +// AddParseTree creates a new template with the name and parse tree +// and associates it with t. +func (t *Template) AddParseTree(name string, tree *parse.Tree) (*Template, error) { + if t.common != nil && t.tmpl[name] != nil { + return nil, fmt.Errorf("template: redefinition of template %q", name) + } + nt := t.New(name) + nt.Tree = tree + t.tmpl[name] = nt + return nt, nil +} + +// Templates returns a slice of the templates associated with t, including t +// itself. +func (t *Template) Templates() []*Template { + if t.common == nil { + return nil + } + // Return a slice so we don't expose the map. + m := make([]*Template, 0, len(t.tmpl)) + for _, v := range t.tmpl { + m = append(m, v) + } + return m +} + +// Delims sets the action delimiters to the specified strings, to be used in +// subsequent calls to Parse, ParseFiles, or ParseGlob. Nested template +// definitions will inherit the settings. An empty delimiter stands for the +// corresponding default: {{ or }}. +// The return value is the template, so calls can be chained. +func (t *Template) Delims(left, right string) *Template { + t.leftDelim = left + t.rightDelim = right + return t +} + +// Funcs adds the elements of the argument map to the template's function map. +// It panics if a value in the map is not a function with appropriate return +// type. However, it is legal to overwrite elements of the map. The return +// value is the template, so calls can be chained. +func (t *Template) Funcs(funcMap FuncMap) *Template { + t.init() + addValueFuncs(t.execFuncs, funcMap) + addFuncs(t.parseFuncs, funcMap) + return t +} + +// Lookup returns the template with the given name that is associated with t, +// or nil if there is no such template. +func (t *Template) Lookup(name string) *Template { + if t.common == nil { + return nil + } + return t.tmpl[name] +} + +// Parse parses a string into a template. Nested template definitions will be +// associated with the top-level template t. Parse may be called multiple times +// to parse definitions of templates to associate with t. It is an error if a +// resulting template is non-empty (contains content other than template +// definitions) and would replace a non-empty template with the same name. +// (In multiple calls to Parse with the same receiver template, only one call +// can contain text other than space, comments, and template definitions.) +func (t *Template) Parse(text string) (*Template, error) { + t.init() + trees, err := parse.Parse(t.name, text, t.leftDelim, t.rightDelim, t.parseFuncs, builtins) + if err != nil { + return nil, err + } + // Add the newly parsed trees, including the one for t, into our common structure. + for name, tree := range trees { + // If the name we parsed is the name of this template, overwrite this template. + // The associate method checks it's not a redefinition. + tmpl := t + if name != t.name { + tmpl = t.New(name) + } + // Even if t == tmpl, we need to install it in the common.tmpl map. + if replace, err := t.associate(tmpl, tree); err != nil { + return nil, err + } else if replace { + tmpl.Tree = tree + } + tmpl.leftDelim = t.leftDelim + tmpl.rightDelim = t.rightDelim + } + return t, nil +} + +// associate installs the new template into the group of templates associated +// with t. It is an error to reuse a name except to overwrite an empty +// template. The two are already known to share the common structure. +// The boolean return value reports wither to store this tree as t.Tree. +func (t *Template) associate(new *Template, tree *parse.Tree) (bool, error) { + if new.common != t.common { + panic("internal error: associate not common") + } + name := new.name + if old := t.tmpl[name]; old != nil { + oldIsEmpty := parse.IsEmptyTree(old.Root) + newIsEmpty := parse.IsEmptyTree(tree.Root) + if newIsEmpty { + // Whether old is empty or not, new is empty; no reason to replace old. + return false, nil + } + if !oldIsEmpty { + return false, fmt.Errorf("template: redefinition of template %q", name) + } + } + t.tmpl[name] = new + return true, nil +} diff --git a/src/text/template/testdata/file1.tmpl b/src/text/template/testdata/file1.tmpl new file mode 100644 index 000000000..febf9d9f8 --- /dev/null +++ b/src/text/template/testdata/file1.tmpl @@ -0,0 +1,2 @@ +{{define "x"}}TEXT{{end}} +{{define "dotV"}}{{.V}}{{end}} diff --git a/src/text/template/testdata/file2.tmpl b/src/text/template/testdata/file2.tmpl new file mode 100644 index 000000000..39bf6fb9e --- /dev/null +++ b/src/text/template/testdata/file2.tmpl @@ -0,0 +1,2 @@ +{{define "dot"}}{{.}}{{end}} +{{define "nested"}}{{template "dot" .}}{{end}} diff --git a/src/text/template/testdata/tmpl1.tmpl b/src/text/template/testdata/tmpl1.tmpl new file mode 100644 index 000000000..b72b3a340 --- /dev/null +++ b/src/text/template/testdata/tmpl1.tmpl @@ -0,0 +1,3 @@ +template1 +{{define "x"}}x{{end}} +{{template "y"}} diff --git a/src/text/template/testdata/tmpl2.tmpl b/src/text/template/testdata/tmpl2.tmpl new file mode 100644 index 000000000..16beba6e7 --- /dev/null +++ b/src/text/template/testdata/tmpl2.tmpl @@ -0,0 +1,3 @@ +template2 +{{define "y"}}y{{end}} +{{template "x"}} -- cgit v1.2.1