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Diffstat (limited to 'src/pkg/runtime/rune.go')
| -rw-r--r-- | src/pkg/runtime/rune.go | 219 |
1 files changed, 0 insertions, 219 deletions
diff --git a/src/pkg/runtime/rune.go b/src/pkg/runtime/rune.go deleted file mode 100644 index a9f683581..000000000 --- a/src/pkg/runtime/rune.go +++ /dev/null @@ -1,219 +0,0 @@ -/* - * The authors of this software are Rob Pike and Ken Thompson. - * Copyright (c) 2002 by Lucent Technologies. - * Portions Copyright 2009 The Go Authors. All rights reserved. - * Permission to use, copy, modify, and distribute this software for any - * purpose without fee is hereby granted, provided that this entire notice - * is included in all copies of any software which is or includes a copy - * or modification of this software and in all copies of the supporting - * documentation for such software. - * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED - * WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY - * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY - * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. - */ - -/* - * This code is copied, with slight editing due to type differences, - * from a subset of ../lib9/utf/rune.c - */ - -package runtime - -const ( - bit1 = 7 - bitx = 6 - bit2 = 5 - bit3 = 4 - bit4 = 3 - bit5 = 2 - - t1 = ((1 << (bit1 + 1)) - 1) ^ 0xFF /* 0000 0000 */ - tx = ((1 << (bitx + 1)) - 1) ^ 0xFF /* 1000 0000 */ - t2 = ((1 << (bit2 + 1)) - 1) ^ 0xFF /* 1100 0000 */ - t3 = ((1 << (bit3 + 1)) - 1) ^ 0xFF /* 1110 0000 */ - t4 = ((1 << (bit4 + 1)) - 1) ^ 0xFF /* 1111 0000 */ - t5 = ((1 << (bit5 + 1)) - 1) ^ 0xFF /* 1111 1000 */ - - rune1 = (1 << (bit1 + 0*bitx)) - 1 /* 0000 0000 0111 1111 */ - rune2 = (1 << (bit2 + 1*bitx)) - 1 /* 0000 0111 1111 1111 */ - rune3 = (1 << (bit3 + 2*bitx)) - 1 /* 1111 1111 1111 1111 */ - rune4 = (1 << (bit4 + 3*bitx)) - 1 /* 0001 1111 1111 1111 1111 1111 */ - - maskx = (1 << bitx) - 1 /* 0011 1111 */ - testx = maskx ^ 0xFF /* 1100 0000 */ - - runeerror = 0xFFFD - runeself = 0x80 - - surrogateMin = 0xD800 - surrogateMax = 0xDFFF - - bad = runeerror - - runemax = 0x10FFFF /* maximum rune value */ -) - -/* - * Modified by Wei-Hwa Huang, Google Inc., on 2004-09-24 - * This is a slower but "safe" version of the old chartorune - * that works on strings that are not necessarily null-terminated. - * - * If you know for sure that your string is null-terminated, - * chartorune will be a bit faster. - * - * It is guaranteed not to attempt to access "length" - * past the incoming pointer. This is to avoid - * possible access violations. If the string appears to be - * well-formed but incomplete (i.e., to get the whole Rune - * we'd need to read past str+length) then we'll set the Rune - * to Bad and return 0. - * - * Note that if we have decoding problems for other - * reasons, we return 1 instead of 0. - */ -func charntorune(s string) (rune, int) { - /* When we're not allowed to read anything */ - if len(s) <= 0 { - return bad, 1 - } - - /* - * one character sequence (7-bit value) - * 00000-0007F => T1 - */ - c := s[0] - if c < tx { - return rune(c), 1 - } - - // If we can't read more than one character we must stop - if len(s) <= 1 { - return bad, 1 - } - - /* - * two character sequence (11-bit value) - * 0080-07FF => t2 tx - */ - c1 := s[1] ^ tx - if (c1 & testx) != 0 { - return bad, 1 - } - if c < t3 { - if c < t2 { - return bad, 1 - } - l := ((rune(c) << bitx) | rune(c1)) & rune2 - if l <= rune1 { - return bad, 1 - } - return l, 2 - } - - // If we can't read more than two characters we must stop - if len(s) <= 2 { - return bad, 1 - } - - /* - * three character sequence (16-bit value) - * 0800-FFFF => t3 tx tx - */ - c2 := s[2] ^ tx - if (c2 & testx) != 0 { - return bad, 1 - } - if c < t4 { - l := ((((rune(c) << bitx) | rune(c1)) << bitx) | rune(c2)) & rune3 - if l <= rune2 { - return bad, 1 - } - if surrogateMin <= l && l <= surrogateMax { - return bad, 1 - } - return l, 3 - } - - if len(s) <= 3 { - return bad, 1 - } - - /* - * four character sequence (21-bit value) - * 10000-1FFFFF => t4 tx tx tx - */ - c3 := s[3] ^ tx - if (c3 & testx) != 0 { - return bad, 1 - } - if c < t5 { - l := ((((((rune(c) << bitx) | rune(c1)) << bitx) | rune(c2)) << bitx) | rune(c3)) & rune4 - if l <= rune3 || l > runemax { - return bad, 1 - } - return l, 4 - } - - // Support for 5-byte or longer UTF-8 would go here, but - // since we don't have that, we'll just return bad. - return bad, 1 -} - -// runetochar converts r to bytes and writes the result to str. -// returns the number of bytes generated. -func runetochar(str []byte, r rune) int { - /* runes are signed, so convert to unsigned for range check. */ - c := uint32(r) - /* - * one character sequence - * 00000-0007F => 00-7F - */ - if c <= rune1 { - str[0] = byte(c) - return 1 - } - /* - * two character sequence - * 0080-07FF => t2 tx - */ - if c <= rune2 { - str[0] = byte(t2 | (c >> (1 * bitx))) - str[1] = byte(tx | (c & maskx)) - return 2 - } - - /* - * If the rune is out of range or a surrogate half, convert it to the error rune. - * Do this test here because the error rune encodes to three bytes. - * Doing it earlier would duplicate work, since an out of range - * rune wouldn't have fit in one or two bytes. - */ - if c > runemax { - c = runeerror - } - if surrogateMin <= c && c <= surrogateMax { - c = runeerror - } - - /* - * three character sequence - * 0800-FFFF => t3 tx tx - */ - if c <= rune3 { - str[0] = byte(t3 | (c >> (2 * bitx))) - str[1] = byte(tx | ((c >> (1 * bitx)) & maskx)) - str[2] = byte(tx | (c & maskx)) - return 3 - } - - /* - * four character sequence (21-bit value) - * 10000-1FFFFF => t4 tx tx tx - */ - str[0] = byte(t4 | (c >> (3 * bitx))) - str[1] = byte(tx | ((c >> (2 * bitx)) & maskx)) - str[2] = byte(tx | ((c >> (1 * bitx)) & maskx)) - str[3] = byte(tx | (c & maskx)) - return 4 -} |