// 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 traditionalchinese 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" ) // All is a list of all defined encodings in this package. var All = []encoding.Encoding{Big5} // Big5 is the Big5 encoding, also known as Code Page 950. var Big5 encoding.Encoding = &big5 var big5 = internal.Encoding{ &internal.SimpleEncoding{big5Decoder{}, big5Encoder{}}, "Big5", identifier.Big5, } type big5Decoder struct{ transform.NopResetter } func (big5Decoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { r, size, s := rune(0), 0, "" loop: for ; nSrc < len(src); nSrc += size { switch c0 := src[nSrc]; { case c0 < utf8.RuneSelf: r, size = rune(c0), 1 case 0x81 <= c0 && 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 0xa1 <= c1 && c1 < 0xff: c1 -= 0x62 case c1 < 0x40: r, size = utf8.RuneError, 1 goto write default: r, size = utf8.RuneError, 2 goto write } r, size = '\ufffd', 2 if i := int(c0-0x81)*157 + int(c1); i < len(decode) { if 1133 <= i && i < 1167 { // The two-rune special cases for LATIN CAPITAL / SMALL E WITH CIRCUMFLEX // AND MACRON / CARON are from http://encoding.spec.whatwg.org/#big5 switch i { case 1133: s = "\u00CA\u0304" goto writeStr case 1135: s = "\u00CA\u030C" goto writeStr case 1164: s = "\u00EA\u0304" goto writeStr case 1166: s = "\u00EA\u030C" goto writeStr } } 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) continue loop writeStr: if nDst+len(s) > len(dst) { err = transform.ErrShortDst break loop } nDst += copy(dst[nDst:], s) continue loop } return nDst, nSrc, err } type big5Encoder struct{ transform.NopResetter } func (big5Encoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { r, size := rune(0), 0 for ; nSrc < len(src); nSrc += size { r = rune(src[nSrc]) // Decode a 1-byte rune. if r < utf8.RuneSelf { size = 1 if nDst >= len(dst) { err = transform.ErrShortDst break } dst[nDst] = uint8(r) nDst++ continue } 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 } } } if r >= utf8.RuneSelf { // func init checks that the switch covers all tables. switch { case encode0Low <= r && r < encode0High: if r = rune(encode0[r-encode0Low]); r != 0 { goto write2 } case encode1Low <= r && r < encode1High: if r = rune(encode1[r-encode1Low]); r != 0 { goto write2 } case encode2Low <= r && r < encode2High: if r = rune(encode2[r-encode2Low]); r != 0 { goto write2 } case encode3Low <= r && r < encode3High: if r = rune(encode3[r-encode3Low]); r != 0 { goto write2 } case encode4Low <= r && r < encode4High: if r = rune(encode4[r-encode4Low]); r != 0 { goto write2 } case encode5Low <= r && r < encode5High: if r = rune(encode5[r-encode5Low]); r != 0 { goto write2 } case encode6Low <= r && r < encode6High: if r = rune(encode6[r-encode6Low]); r != 0 { goto write2 } case encode7Low <= r && r < encode7High: if r = rune(encode7[r-encode7Low]); r != 0 { goto write2 } } err = internal.ErrASCIIReplacement break } write2: if nDst+2 > len(dst) { err = transform.ErrShortDst break } dst[nDst+0] = uint8(r >> 8) dst[nDst+1] = uint8(r) nDst += 2 continue } return nDst, nSrc, err } func init() { // Check that the hard-coded encode switch covers all tables. if numEncodeTables != 8 { panic("bad numEncodeTables") } }