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-rw-r--r--libgo/go/time/format.go271
1 files changed, 189 insertions, 82 deletions
diff --git a/libgo/go/time/format.go b/libgo/go/time/format.go
index f11fb7ed304..bb173a21c2d 100644
--- a/libgo/go/time/format.go
+++ b/libgo/go/time/format.go
@@ -7,70 +7,89 @@ package time
import "errors"
// These are predefined layouts for use in Time.Format and time.Parse.
-// The reference time used in the layouts is the specific time:
-// Mon Jan 2 15:04:05 MST 2006
-// which is Unix time 1136239445. Since MST is GMT-0700,
-// the reference time can be thought of as
+// The reference time used in these layouts is the specific time stamp:
// 01/02 03:04:05PM '06 -0700
-// To define your own format, write down what the reference time would look
-// like formatted your way; see the values of constants like ANSIC,
-// StampMicro or Kitchen for examples. The model is to demonstrate what the
-// reference time looks like so that the Format and Parse methods can apply
-// the same transformation to a general time value.
+// (January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
+// That value is recorded as the constant named Layout, listed below. As a Unix
+// time, this is 1136239445. Since MST is GMT-0700, the reference would be
+// printed by the Unix date command as:
+// Mon Jan 2 15:04:05 MST 2006
+// It is a regrettable historic error that the date uses the American convention
+// of putting the numerical month before the day.
//
-// Some valid layouts are invalid time values for time.Parse, due to formats
-// such as _ for space padding and Z for zone information.
+// The example for Time.Format demonstrates the working of the layout string
+// in detail and is a good reference.
//
-// Within the format string, an underscore _ represents a space that may be
-// replaced by a digit if the following number (a day) has two digits; for
-// compatibility with fixed-width Unix time formats.
+// Note that the RFC822, RFC850, and RFC1123 formats should be applied
+// only to local times. Applying them to UTC times will use "UTC" as the
+// time zone abbreviation, while strictly speaking those RFCs require the
+// use of "GMT" in that case.
+// In general RFC1123Z should be used instead of RFC1123 for servers
+// that insist on that format, and RFC3339 should be preferred for new protocols.
+// RFC3339, RFC822, RFC822Z, RFC1123, and RFC1123Z are useful for formatting;
+// when used with time.Parse they do not accept all the time formats
+// permitted by the RFCs and they do accept time formats not formally defined.
+// The RFC3339Nano format removes trailing zeros from the seconds field
+// and thus may not sort correctly once formatted.
//
-// A decimal point followed by one or more zeros represents a fractional
-// second, printed to the given number of decimal places. A decimal point
-// followed by one or more nines represents a fractional second, printed to
-// the given number of decimal places, with trailing zeros removed.
-// When parsing (only), the input may contain a fractional second
-// field immediately after the seconds field, even if the layout does not
-// signify its presence. In that case a decimal point followed by a maximal
-// series of digits is parsed as a fractional second.
+// Most programs can use one of the defined constants as the layout passed to
+// Format or Parse. The rest of this comment can be ignored unless you are
+// creating a custom layout string.
+//
+// To define your own format, write down what the reference time would look like
+// formatted your way; see the values of constants like ANSIC, StampMicro or
+// Kitchen for examples. The model is to demonstrate what the reference time
+// looks like so that the Format and Parse methods can apply the same
+// transformation to a general time value.
+//
+// Here is a summary of the components of a layout string. Each element shows by
+// example the formatting of an element of the reference time. Only these values
+// are recognized. Text in the layout string that is not recognized as part of
+// the reference time is echoed verbatim during Format and expected to appear
+// verbatim in the input to Parse.
+//
+// Year: "2006" "06"
+// Month: "Jan" "January"
+// Textual day of the week: "Mon" "Monday"
+// Numeric day of the month: "2" "_2" "02"
+// Numeric day of the year: "__2" "002"
+// Hour: "15" "3" "03" (PM or AM)
+// Minute: "4" "04"
+// Second: "5" "05"
+// AM/PM mark: "PM"
//
// Numeric time zone offsets format as follows:
-// -0700 ±hhmm
-// -07:00 ±hh:mm
-// -07 ±hh
+// "-0700" ±hhmm
+// "-07:00" ±hh:mm
+// "-07" ±hh
// Replacing the sign in the format with a Z triggers
// the ISO 8601 behavior of printing Z instead of an
// offset for the UTC zone. Thus:
-// Z0700 Z or ±hhmm
-// Z07:00 Z or ±hh:mm
-// Z07 Z or ±hh
+// "Z0700" Z or ±hhmm
+// "Z07:00" Z or ±hh:mm
+// "Z07" Z or ±hh
//
-// The recognized day of week formats are "Mon" and "Monday".
-// The recognized month formats are "Jan" and "January".
+// Within the format string, the underscores in "_2" and "__2" represent spaces
+// that may be replaced by digits if the following number has multiple digits,
+// for compatibility with fixed-width Unix time formats. A leading zero represents
+// a zero-padded value.
//
-// The formats 2, _2, and 02 are unpadded, space-padded, and zero-padded
-// day of month. The formats __2 and 002 are space-padded and zero-padded
+// The formats and 002 are space-padded and zero-padded
// three-character day of year; there is no unpadded day of year format.
//
-// Text in the format string that is not recognized as part of the reference
-// time is echoed verbatim during Format and expected to appear verbatim
-// in the input to Parse.
+// A decimal point followed by one or more zeros represents a fractional
+// second, printed to the given number of decimal places.
+// Either a comma or decimal point followed by one or more nines represents
+// a fractional second, printed to the given number of decimal places, with
+// trailing zeros removed.
+// For example "15:04:05,000" or "15:04:05.000" formats or parses with
+// millisecond precision.
//
-// The executable example for Time.Format demonstrates the working
-// of the layout string in detail and is a good reference.
+// Some valid layouts are invalid time values for time.Parse, due to formats
+// such as _ for space padding and Z for zone information.
//
-// Note that the RFC822, RFC850, and RFC1123 formats should be applied
-// only to local times. Applying them to UTC times will use "UTC" as the
-// time zone abbreviation, while strictly speaking those RFCs require the
-// use of "GMT" in that case.
-// In general RFC1123Z should be used instead of RFC1123 for servers
-// that insist on that format, and RFC3339 should be preferred for new protocols.
-// RFC3339, RFC822, RFC822Z, RFC1123, and RFC1123Z are useful for formatting;
-// when used with time.Parse they do not accept all the time formats
-// permitted by the RFCs and they do accept time formats not formally defined.
-// The RFC3339Nano format removes trailing zeros from the seconds field
-// and thus may not sort correctly once formatted.
const (
+ Layout = "01/02 03:04:05PM '06 -0700" // The reference time, in numerical order.
ANSIC = "Mon Jan _2 15:04:05 2006"
UnixDate = "Mon Jan _2 15:04:05 MST 2006"
RubyDate = "Mon Jan 02 15:04:05 -0700 2006"
@@ -261,7 +280,7 @@ func nextStdChunk(layout string) (prefix string, std int, suffix string) {
return layout[0:i], stdISO8601ShortTZ, layout[i+3:]
}
- case '.': // .000 or .999 - repeated digits for fractional seconds.
+ case '.', ',': // ,000, or .000, or ,999, or .999 - repeated digits for fractional seconds.
if i+1 < len(layout) && (layout[i+1] == '0' || layout[i+1] == '9') {
ch := layout[i+1]
j := i + 1
@@ -476,22 +495,66 @@ func (t Time) String() string {
return s
}
-// Format returns a textual representation of the time value formatted
-// according to layout, which defines the format by showing how the reference
-// time, defined to be
-// Mon Jan 2 15:04:05 -0700 MST 2006
-// would be displayed if it were the value; it serves as an example of the
-// desired output. The same display rules will then be applied to the time
-// value.
-//
-// A fractional second is represented by adding a period and zeros
-// to the end of the seconds section of layout string, as in "15:04:05.000"
-// to format a time stamp with millisecond precision.
+// GoString implements fmt.GoStringer and formats t to be printed in Go source
+// code.
+func (t Time) GoString() string {
+ buf := []byte("time.Date(")
+ buf = appendInt(buf, t.Year(), 0)
+ month := t.Month()
+ if January <= month && month <= December {
+ buf = append(buf, ", time."...)
+ buf = append(buf, t.Month().String()...)
+ } else {
+ // It's difficult to construct a time.Time with a date outside the
+ // standard range but we might as well try to handle the case.
+ buf = appendInt(buf, int(month), 0)
+ }
+ buf = append(buf, ", "...)
+ buf = appendInt(buf, t.Day(), 0)
+ buf = append(buf, ", "...)
+ buf = appendInt(buf, t.Hour(), 0)
+ buf = append(buf, ", "...)
+ buf = appendInt(buf, t.Minute(), 0)
+ buf = append(buf, ", "...)
+ buf = appendInt(buf, t.Second(), 0)
+ buf = append(buf, ", "...)
+ buf = appendInt(buf, t.Nanosecond(), 0)
+ buf = append(buf, ", "...)
+ switch loc := t.Location(); loc {
+ case UTC, nil:
+ buf = append(buf, "time.UTC"...)
+ case Local:
+ buf = append(buf, "time.Local"...)
+ default:
+ // there are several options for how we could display this, none of
+ // which are great:
+ //
+ // - use Location(loc.name), which is not technically valid syntax
+ // - use LoadLocation(loc.name), which will cause a syntax error when
+ // embedded and also would require us to escape the string without
+ // importing fmt or strconv
+ // - try to use FixedZone, which would also require escaping the name
+ // and would represent e.g. "America/Los_Angeles" daylight saving time
+ // shifts inaccurately
+ // - use the pointer format, which is no worse than you'd get with the
+ // old fmt.Sprintf("%#v", t) format.
+ //
+ // Of these, Location(loc.name) is the least disruptive. This is an edge
+ // case we hope not to hit too often.
+ buf = append(buf, `time.Location(`...)
+ buf = append(buf, []byte(quote(loc.name))...)
+ buf = append(buf, `)`...)
+ }
+ buf = append(buf, ')')
+ return string(buf)
+}
+
+// Format returns a textual representation of the time value formatted according
+// to the layout defined by the argument. See the documentation for the
+// constant called Layout to see how to represent the layout format.
//
-// Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard
-// and convenient representations of the reference time. For more information
-// about the formats and the definition of the reference time, see the
-// documentation for ANSIC and the other constants defined by this package.
+// The executable example for Time.Format demonstrates the working
+// of the layout string in detail and is a good reference.
func (t Time) Format(layout string) string {
const bufSize = 64
var b []byte
@@ -686,8 +749,48 @@ type ParseError struct {
Message string
}
+// These are borrowed from unicode/utf8 and strconv and replicate behavior in
+// that package, since we can't take a dependency on either.
+const (
+ lowerhex = "0123456789abcdef"
+ runeSelf = 0x80
+ runeError = '\uFFFD'
+)
+
func quote(s string) string {
- return "\"" + s + "\""
+ buf := make([]byte, 1, len(s)+2) // slice will be at least len(s) + quotes
+ buf[0] = '"'
+ for i, c := range s {
+ if c >= runeSelf || c < ' ' {
+ // This means you are asking us to parse a time.Duration or
+ // time.Location with unprintable or non-ASCII characters in it.
+ // We don't expect to hit this case very often. We could try to
+ // reproduce strconv.Quote's behavior with full fidelity but
+ // given how rarely we expect to hit these edge cases, speed and
+ // conciseness are better.
+ var width int
+ if c == runeError {
+ width = 1
+ if i+2 < len(s) && s[i:i+3] == string(runeError) {
+ width = 3
+ }
+ } else {
+ width = len(string(c))
+ }
+ for j := 0; j < width; j++ {
+ buf = append(buf, `\x`...)
+ buf = append(buf, lowerhex[s[i+j]>>4])
+ buf = append(buf, lowerhex[s[i+j]&0xF])
+ }
+ } else {
+ if c == '"' || c == '\\' {
+ buf = append(buf, '\\')
+ }
+ buf = append(buf, string(c)...)
+ }
+ }
+ buf = append(buf, '"')
+ return string(buf)
}
// Error returns the string representation of a ParseError.
@@ -771,21 +874,19 @@ func skip(value, prefix string) (string, error) {
}
// Parse parses a formatted string and returns the time value it represents.
-// The layout defines the format by showing how the reference time,
-// defined to be
-// Mon Jan 2 15:04:05 -0700 MST 2006
-// would be interpreted if it were the value; it serves as an example of
-// the input format. The same interpretation will then be made to the
-// input string.
+// See the documentation for the constant called Layout to see how to
+// represent the format. The second argument must be parseable using
+// the format string (layout) provided as the first argument.
//
-// Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard
-// and convenient representations of the reference time. For more information
-// about the formats and the definition of the reference time, see the
-// documentation for ANSIC and the other constants defined by this package.
-// Also, the executable example for Time.Format demonstrates the working
-// of the layout string in detail and is a good reference.
+// The example for Time.Format demonstrates the working of the layout string
+// in detail and is a good reference.
+//
+// When parsing (only), the input may contain a fractional second
+// field immediately after the seconds field, even if the layout does not
+// signify its presence. In that case either a comma or a decimal point
+// followed by a maximal series of digits is parsed as a fractional second.
//
-// Elements omitted from the value are assumed to be zero or, when
+// Elements omitted from the layout are assumed to be zero or, when
// zero is impossible, one, so parsing "3:04pm" returns the time
// corresponding to Jan 1, year 0, 15:04:00 UTC (note that because the year is
// 0, this time is before the zero Time).
@@ -795,6 +896,8 @@ func skip(value, prefix string) (string, error) {
// For layouts specifying the two-digit year 06, a value NN >= 69 will be treated
// as 19NN and a value NN < 69 will be treated as 20NN.
//
+// The remainder of this comment describes the handling of time zones.
+//
// In the absence of a time zone indicator, Parse returns a time in UTC.
//
// When parsing a time with a zone offset like -0700, if the offset corresponds
@@ -940,7 +1043,7 @@ func parse(layout, value string, defaultLocation, local *Location) (Time, error)
}
// Special case: do we have a fractional second but no
// fractional second in the format?
- if len(value) >= 2 && value[0] == '.' && isDigit(value, 1) {
+ if len(value) >= 2 && commaOrPeriod(value[0]) && isDigit(value, 1) {
_, std, _ = nextStdChunk(layout)
std &= stdMask
if std == stdFracSecond0 || std == stdFracSecond9 {
@@ -1070,7 +1173,7 @@ func parse(layout, value string, defaultLocation, local *Location) (Time, error)
value = value[ndigit:]
case stdFracSecond9:
- if len(value) < 2 || value[0] != '.' || value[1] < '0' || '9' < value[1] {
+ if len(value) < 2 || !commaOrPeriod(value[0]) || value[1] < '0' || '9' < value[1] {
// Fractional second omitted.
break
}
@@ -1152,7 +1255,7 @@ func parse(layout, value string, defaultLocation, local *Location) (Time, error)
// Look for local zone with the given offset.
// If that zone was in effect at the given time, use it.
- name, offset, _, _ := local.lookup(t.unixSec())
+ name, offset, _, _, _ := local.lookup(t.unixSec())
if offset == zoneOffset && (zoneName == "" || name == zoneName) {
t.setLoc(local)
return t, nil
@@ -1279,8 +1382,12 @@ func parseSignedOffset(value string) int {
return len(value) - len(rem)
}
+func commaOrPeriod(b byte) bool {
+ return b == '.' || b == ','
+}
+
func parseNanoseconds(value string, nbytes int) (ns int, rangeErrString string, err error) {
- if value[0] != '.' {
+ if !commaOrPeriod(value[0]) {
err = errBad
return
}
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