// 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 korean
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{EUCKR}
// EUCKR is the EUC-KR encoding, also known as Code Page 949.
var EUCKR encoding.Encoding = &eucKR
var eucKR = internal.Encoding{
&internal.SimpleEncoding{eucKRDecoder{}, eucKREncoder{}},
"EUC-KR",
identifier.EUCKR,
}
var errInvalidEUCKR = errors.New("korean: invalid EUC-KR encoding")
type eucKRDecoder struct{ transform.NopResetter }
func (eucKRDecoder) 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 0x81 <= c0 && c0 < 0xff:
if nSrc+1 >= len(src) {
err = transform.ErrShortSrc
break loop
}
c1 := src[nSrc+1]
if c0 < 0xc7 {
r = 178 * rune(c0-0x81)
switch {
case 0x41 <= c1 && c1 < 0x5b:
r += rune(c1) - (0x41 - 0*26)
case 0x61 <= c1 && c1 < 0x7b:
r += rune(c1) - (0x61 - 1*26)
case 0x81 <= c1 && c1 < 0xff:
r += rune(c1) - (0x81 - 2*26)
default:
err = errInvalidEUCKR
break loop
}
} else if 0xa1 <= c1 && c1 < 0xff {
r = 178*(0xc7-0x81) + rune(c0-0xc7)*94 + rune(c1-0xa1)
} else {
err = errInvalidEUCKR
break loop
}
if int(r) < len(decode) {
r = rune(decode[r])
if r == 0 {
r = '\ufffd'
}
} else {
r = '\ufffd'
}
size = 2
default:
err = errInvalidEUCKR
break loop
}
if nDst+utf8.RuneLen(r) > len(dst) {
err = transform.ErrShortDst
break loop
}
nDst += utf8.EncodeRune(dst[nDst:], r)
}
if atEOF && err == transform.ErrShortSrc {
err = errInvalidEUCKR
}
return nDst, nSrc, err
}
type eucKREncoder struct{ transform.NopResetter }
func (eucKREncoder) 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
}
}
// 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
}
}
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 != 7 {
panic("bad numEncodeTables")
}
}