// 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 japanese 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" ) // ShiftJIS is the Shift JIS encoding, also known as Code Page 932 and // Windows-31J. var ShiftJIS encoding.Encoding = &shiftJIS var shiftJIS = internal.Encoding{ &internal.SimpleEncoding{shiftJISDecoder{}, shiftJISEncoder{}}, "Shift JIS", identifier.ShiftJIS, } type shiftJISDecoder struct{ transform.NopResetter } func (shiftJISDecoder) 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 case 0xa1 <= c0 && c0 < 0xe0: r, size = rune(c0)+(0xff61-0xa1), 1 case (0x81 <= c0 && c0 < 0xa0) || (0xe0 <= c0 && c0 < 0xfd): if c0 <= 0x9f { c0 -= 0x70 } else { c0 -= 0xb0 } c0 = 2*c0 - 0x21 if nSrc+1 >= len(src) { if !atEOF { err = transform.ErrShortSrc break loop } r, size = '\ufffd', 1 goto write } c1 := src[nSrc+1] switch { case c1 < 0x40: r, size = '\ufffd', 1 // c1 is ASCII so output on next round goto write case c1 < 0x7f: c0-- c1 -= 0x40 case c1 == 0x7f: r, size = '\ufffd', 1 // c1 is ASCII so output on next round goto write case c1 < 0x9f: c0-- c1 -= 0x41 case c1 < 0xfd: c1 -= 0x9f default: r, size = '\ufffd', 2 goto write } r, size = '\ufffd', 2 if i := int(c0)*94 + int(c1); i < len(jis0208Decode) { r = rune(jis0208Decode[i]) if r == 0 { r = '\ufffd' } } case c0 == 0x80: r, size = 0x80, 1 default: r, size = '\ufffd', 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 shiftJISEncoder struct{ transform.NopResetter } func (shiftJISEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { r, size := rune(0), 0 loop: 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 loop } } // func init checks that the switch covers all tables. switch { case encode0Low <= r && r < encode0High: if r = rune(encode0[r-encode0Low]); r>>tableShift == jis0208 { goto write2 } case encode1Low <= r && r < encode1High: if r = rune(encode1[r-encode1Low]); r>>tableShift == jis0208 { goto write2 } case encode2Low <= r && r < encode2High: if r = rune(encode2[r-encode2Low]); r>>tableShift == jis0208 { goto write2 } case encode3Low <= r && r < encode3High: if r = rune(encode3[r-encode3Low]); r>>tableShift == jis0208 { goto write2 } case encode4Low <= r && r < encode4High: if r = rune(encode4[r-encode4Low]); r>>tableShift == jis0208 { goto write2 } case encode5Low <= r && r < encode5High: if 0xff61 <= r && r < 0xffa0 { r -= 0xff61 - 0xa1 goto write1 } if r = rune(encode5[r-encode5Low]); r>>tableShift == jis0208 { goto write2 } } err = internal.ErrASCIIReplacement break } write1: if nDst >= len(dst) { err = transform.ErrShortDst break } dst[nDst] = uint8(r) nDst++ continue write2: j1 := uint8(r>>codeShift) & codeMask j2 := uint8(r) & codeMask if nDst+2 > len(dst) { err = transform.ErrShortDst break loop } if j1 <= 61 { dst[nDst+0] = 129 + j1/2 } else { dst[nDst+0] = 193 + j1/2 } if j1&1 == 0 { dst[nDst+1] = j2 + j2/63 + 64 } else { dst[nDst+1] = j2 + 159 } nDst += 2 continue } return nDst, nSrc, err }