--- /dev/null
+// Copyright 2013 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 simplifiedchinese
+
+import (
+ "unicode/utf8"
+
+ "golang.org/x/text/encoding"
+ "golang.org/x/text/encoding/internal"
+ "golang.org/x/text/encoding/internal/identifier"
+ "golang.org/x/text/transform"
+)
+
+var (
+ // GB18030 is the GB18030 encoding.
+ GB18030 encoding.Encoding = &gbk18030
+ // GBK is the GBK encoding. It encodes an extension of the GB2312 character set
+ // and is also known as Code Page 936.
+ GBK encoding.Encoding = &gbk
+)
+
+var gbk = internal.Encoding{
+ &internal.SimpleEncoding{
+ gbkDecoder{gb18030: false},
+ gbkEncoder{gb18030: false},
+ },
+ "GBK",
+ identifier.GBK,
+}
+
+var gbk18030 = internal.Encoding{
+ &internal.SimpleEncoding{
+ gbkDecoder{gb18030: true},
+ gbkEncoder{gb18030: true},
+ },
+ "GB18030",
+ identifier.GB18030,
+}
+
+type gbkDecoder struct {
+ transform.NopResetter
+ gb18030 bool
+}
+
+func (d gbkDecoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ r, size := rune(0), 0
+loop:
+ for ; nSrc < len(src); nSrc += size {
+ switch c0 := src[nSrc]; {
+ case c0 < utf8.RuneSelf:
+ r, size = rune(c0), 1
+
+ // Microsoft's Code Page 936 extends GBK 1.0 to encode the euro sign U+20AC
+ // as 0x80. The HTML5 specification at http://encoding.spec.whatwg.org/#gbk
+ // says to treat "gbk" as Code Page 936.
+ case c0 == 0x80:
+ r, size = '€', 1
+
+ case c0 < 0xff:
+ if nSrc+1 >= len(src) {
+ if !atEOF {
+ err = transform.ErrShortSrc
+ break loop
+ }
+ r, size = utf8.RuneError, 1
+ goto write
+ }
+ c1 := src[nSrc+1]
+ switch {
+ case 0x40 <= c1 && c1 < 0x7f:
+ c1 -= 0x40
+ case 0x80 <= c1 && c1 < 0xff:
+ c1 -= 0x41
+ case d.gb18030 && 0x30 <= c1 && c1 < 0x40:
+ if nSrc+3 >= len(src) {
+ if !atEOF {
+ err = transform.ErrShortSrc
+ break loop
+ }
+ // The second byte here is always ASCII, so we can set size
+ // to 1 in all cases.
+ r, size = utf8.RuneError, 1
+ goto write
+ }
+ c2 := src[nSrc+2]
+ if c2 < 0x81 || 0xff <= c2 {
+ r, size = utf8.RuneError, 1
+ goto write
+ }
+ c3 := src[nSrc+3]
+ if c3 < 0x30 || 0x3a <= c3 {
+ r, size = utf8.RuneError, 1
+ goto write
+ }
+ size = 4
+ r = ((rune(c0-0x81)*10+rune(c1-0x30))*126+rune(c2-0x81))*10 + rune(c3-0x30)
+ if r < 39420 {
+ i, j := 0, len(gb18030)
+ for i < j {
+ h := i + (j-i)/2
+ if r >= rune(gb18030[h][0]) {
+ i = h + 1
+ } else {
+ j = h
+ }
+ }
+ dec := &gb18030[i-1]
+ r += rune(dec[1]) - rune(dec[0])
+ goto write
+ }
+ r -= 189000
+ if 0 <= r && r < 0x100000 {
+ r += 0x10000
+ } else {
+ r, size = utf8.RuneError, 1
+ }
+ goto write
+ default:
+ r, size = utf8.RuneError, 1
+ goto write
+ }
+ r, size = '\ufffd', 2
+ if i := int(c0-0x81)*190 + int(c1); i < len(decode) {
+ r = rune(decode[i])
+ if r == 0 {
+ r = '\ufffd'
+ }
+ }
+
+ default:
+ r, size = utf8.RuneError, 1
+ }
+
+ write:
+ if nDst+utf8.RuneLen(r) > len(dst) {
+ err = transform.ErrShortDst
+ break loop
+ }
+ nDst += utf8.EncodeRune(dst[nDst:], r)
+ }
+ return nDst, nSrc, err
+}
+
+type gbkEncoder struct {
+ transform.NopResetter
+ gb18030 bool
+}
+
+func (e gbkEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ r, r2, size := rune(0), rune(0), 0
+ for ; nSrc < len(src); nSrc += size {
+ r = rune(src[nSrc])
+
+ // Decode a 1-byte rune.
+ if r < utf8.RuneSelf {
+ size = 1
+
+ } else {
+ // Decode a multi-byte rune.
+ r, size = utf8.DecodeRune(src[nSrc:])
+ if size == 1 {
+ // All valid runes of size 1 (those below utf8.RuneSelf) were
+ // handled above. We have invalid UTF-8 or we haven't seen the
+ // full character yet.
+ if !atEOF && !utf8.FullRune(src[nSrc:]) {
+ err = transform.ErrShortSrc
+ break
+ }
+ }
+
+ // func init checks that the switch covers all tables.
+ switch {
+ case encode0Low <= r && r < encode0High:
+ if r2 = rune(encode0[r-encode0Low]); r2 != 0 {
+ goto write2
+ }
+ case encode1Low <= r && r < encode1High:
+ // Microsoft's Code Page 936 extends GBK 1.0 to encode the euro sign U+20AC
+ // as 0x80. The HTML5 specification at http://encoding.spec.whatwg.org/#gbk
+ // says to treat "gbk" as Code Page 936.
+ if r == '€' {
+ r = 0x80
+ goto write1
+ }
+ if r2 = rune(encode1[r-encode1Low]); r2 != 0 {
+ goto write2
+ }
+ case encode2Low <= r && r < encode2High:
+ if r2 = rune(encode2[r-encode2Low]); r2 != 0 {
+ goto write2
+ }
+ case encode3Low <= r && r < encode3High:
+ if r2 = rune(encode3[r-encode3Low]); r2 != 0 {
+ goto write2
+ }
+ case encode4Low <= r && r < encode4High:
+ if r2 = rune(encode4[r-encode4Low]); r2 != 0 {
+ goto write2
+ }
+ }
+
+ if e.gb18030 {
+ if r < 0x10000 {
+ i, j := 0, len(gb18030)
+ for i < j {
+ h := i + (j-i)/2
+ if r >= rune(gb18030[h][1]) {
+ i = h + 1
+ } else {
+ j = h
+ }
+ }
+ dec := &gb18030[i-1]
+ r += rune(dec[0]) - rune(dec[1])
+ goto write4
+ } else if r < 0x110000 {
+ r += 189000 - 0x10000
+ goto write4
+ }
+ }
+ err = internal.ErrASCIIReplacement
+ break
+ }
+
+ write1:
+ if nDst >= len(dst) {
+ err = transform.ErrShortDst
+ break
+ }
+ dst[nDst] = uint8(r)
+ nDst++
+ continue
+
+ write2:
+ if nDst+2 > len(dst) {
+ err = transform.ErrShortDst
+ break
+ }
+ dst[nDst+0] = uint8(r2 >> 8)
+ dst[nDst+1] = uint8(r2)
+ nDst += 2
+ continue
+
+ write4:
+ if nDst+4 > len(dst) {
+ err = transform.ErrShortDst
+ break
+ }
+ dst[nDst+3] = uint8(r%10 + 0x30)
+ r /= 10
+ dst[nDst+2] = uint8(r%126 + 0x81)
+ r /= 126
+ dst[nDst+1] = uint8(r%10 + 0x30)
+ r /= 10
+ dst[nDst+0] = uint8(r + 0x81)
+ nDst += 4
+ continue
+ }
+ return nDst, nSrc, err
+}
+
+func init() {
+ // Check that the hard-coded encode switch covers all tables.
+ if numEncodeTables != 5 {
+ panic("bad numEncodeTables")
+ }
+}
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