diff options
Diffstat (limited to 'vendor/golang.org/x/text/encoding/traditionalchinese/big5.go')
-rw-r--r-- | vendor/golang.org/x/text/encoding/traditionalchinese/big5.go | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/encoding/traditionalchinese/big5.go b/vendor/golang.org/x/text/encoding/traditionalchinese/big5.go new file mode 100644 index 000000000..275821f5d --- /dev/null +++ b/vendor/golang.org/x/text/encoding/traditionalchinese/big5.go @@ -0,0 +1,198 @@ +// 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 ( + "errors" + "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, +} + +var errInvalidBig5 = errors.New("traditionalchinese: invalid Big5 encoding") + +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) { + err = transform.ErrShortSrc + break loop + } + c1 := src[nSrc+1] + switch { + case 0x40 <= c1 && c1 < 0x7f: + c1 -= 0x40 + case 0xa1 <= c1 && c1 < 0xff: + c1 -= 0x62 + default: + err = errInvalidBig5 + break loop + } + 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: + err = errInvalidBig5 + break loop + } + + 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 + } + if atEOF && err == transform.ErrShortSrc { + err = errInvalidBig5 + } + 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") + } +} |