forked from jshiffer/matterbridge
8764be7461
* Add vk bridge * Vk bridge attachments * Vk bridge forwarded messages * Vk bridge sample config and code cleanup * Vk bridge add vendor * Vk bridge message edit * Vk bridge: fix fetching names of other bots * Vk bridge: code cleanup * Vk bridge: fix shadows declaration * Vk bridge: remove UseFileURL
250 lines
6.4 KiB
Go
250 lines
6.4 KiB
Go
// 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.
|
|
|
|
//go:generate go run maketables.go
|
|
|
|
// Package charmap provides simple character encodings such as IBM Code Page 437
|
|
// and Windows 1252.
|
|
package charmap // import "golang.org/x/text/encoding/charmap"
|
|
|
|
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"
|
|
)
|
|
|
|
// These encodings vary only in the way clients should interpret them. Their
|
|
// coded character set is identical and a single implementation can be shared.
|
|
var (
|
|
// ISO8859_6E is the ISO 8859-6E encoding.
|
|
ISO8859_6E encoding.Encoding = &iso8859_6E
|
|
|
|
// ISO8859_6I is the ISO 8859-6I encoding.
|
|
ISO8859_6I encoding.Encoding = &iso8859_6I
|
|
|
|
// ISO8859_8E is the ISO 8859-8E encoding.
|
|
ISO8859_8E encoding.Encoding = &iso8859_8E
|
|
|
|
// ISO8859_8I is the ISO 8859-8I encoding.
|
|
ISO8859_8I encoding.Encoding = &iso8859_8I
|
|
|
|
iso8859_6E = internal.Encoding{
|
|
Encoding: ISO8859_6,
|
|
Name: "ISO-8859-6E",
|
|
MIB: identifier.ISO88596E,
|
|
}
|
|
|
|
iso8859_6I = internal.Encoding{
|
|
Encoding: ISO8859_6,
|
|
Name: "ISO-8859-6I",
|
|
MIB: identifier.ISO88596I,
|
|
}
|
|
|
|
iso8859_8E = internal.Encoding{
|
|
Encoding: ISO8859_8,
|
|
Name: "ISO-8859-8E",
|
|
MIB: identifier.ISO88598E,
|
|
}
|
|
|
|
iso8859_8I = internal.Encoding{
|
|
Encoding: ISO8859_8,
|
|
Name: "ISO-8859-8I",
|
|
MIB: identifier.ISO88598I,
|
|
}
|
|
)
|
|
|
|
// All is a list of all defined encodings in this package.
|
|
var All []encoding.Encoding = listAll
|
|
|
|
// TODO: implement these encodings, in order of importance.
|
|
// ASCII, ISO8859_1: Rather common. Close to Windows 1252.
|
|
// ISO8859_9: Close to Windows 1254.
|
|
|
|
// utf8Enc holds a rune's UTF-8 encoding in data[:len].
|
|
type utf8Enc struct {
|
|
len uint8
|
|
data [3]byte
|
|
}
|
|
|
|
// Charmap is an 8-bit character set encoding.
|
|
type Charmap struct {
|
|
// name is the encoding's name.
|
|
name string
|
|
// mib is the encoding type of this encoder.
|
|
mib identifier.MIB
|
|
// asciiSuperset states whether the encoding is a superset of ASCII.
|
|
asciiSuperset bool
|
|
// low is the lower bound of the encoded byte for a non-ASCII rune. If
|
|
// Charmap.asciiSuperset is true then this will be 0x80, otherwise 0x00.
|
|
low uint8
|
|
// replacement is the encoded replacement character.
|
|
replacement byte
|
|
// decode is the map from encoded byte to UTF-8.
|
|
decode [256]utf8Enc
|
|
// encoding is the map from runes to encoded bytes. Each entry is a
|
|
// uint32: the high 8 bits are the encoded byte and the low 24 bits are
|
|
// the rune. The table entries are sorted by ascending rune.
|
|
encode [256]uint32
|
|
}
|
|
|
|
// NewDecoder implements the encoding.Encoding interface.
|
|
func (m *Charmap) NewDecoder() *encoding.Decoder {
|
|
return &encoding.Decoder{Transformer: charmapDecoder{charmap: m}}
|
|
}
|
|
|
|
// NewEncoder implements the encoding.Encoding interface.
|
|
func (m *Charmap) NewEncoder() *encoding.Encoder {
|
|
return &encoding.Encoder{Transformer: charmapEncoder{charmap: m}}
|
|
}
|
|
|
|
// String returns the Charmap's name.
|
|
func (m *Charmap) String() string {
|
|
return m.name
|
|
}
|
|
|
|
// ID implements an internal interface.
|
|
func (m *Charmap) ID() (mib identifier.MIB, other string) {
|
|
return m.mib, ""
|
|
}
|
|
|
|
// charmapDecoder implements transform.Transformer by decoding to UTF-8.
|
|
type charmapDecoder struct {
|
|
transform.NopResetter
|
|
charmap *Charmap
|
|
}
|
|
|
|
func (m charmapDecoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
|
|
for i, c := range src {
|
|
if m.charmap.asciiSuperset && c < utf8.RuneSelf {
|
|
if nDst >= len(dst) {
|
|
err = transform.ErrShortDst
|
|
break
|
|
}
|
|
dst[nDst] = c
|
|
nDst++
|
|
nSrc = i + 1
|
|
continue
|
|
}
|
|
|
|
decode := &m.charmap.decode[c]
|
|
n := int(decode.len)
|
|
if nDst+n > len(dst) {
|
|
err = transform.ErrShortDst
|
|
break
|
|
}
|
|
// It's 15% faster to avoid calling copy for these tiny slices.
|
|
for j := 0; j < n; j++ {
|
|
dst[nDst] = decode.data[j]
|
|
nDst++
|
|
}
|
|
nSrc = i + 1
|
|
}
|
|
return nDst, nSrc, err
|
|
}
|
|
|
|
// DecodeByte returns the Charmap's rune decoding of the byte b.
|
|
func (m *Charmap) DecodeByte(b byte) rune {
|
|
switch x := &m.decode[b]; x.len {
|
|
case 1:
|
|
return rune(x.data[0])
|
|
case 2:
|
|
return rune(x.data[0]&0x1f)<<6 | rune(x.data[1]&0x3f)
|
|
default:
|
|
return rune(x.data[0]&0x0f)<<12 | rune(x.data[1]&0x3f)<<6 | rune(x.data[2]&0x3f)
|
|
}
|
|
}
|
|
|
|
// charmapEncoder implements transform.Transformer by encoding from UTF-8.
|
|
type charmapEncoder struct {
|
|
transform.NopResetter
|
|
charmap *Charmap
|
|
}
|
|
|
|
func (m charmapEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
|
|
r, size := rune(0), 0
|
|
loop:
|
|
for nSrc < len(src) {
|
|
if nDst >= len(dst) {
|
|
err = transform.ErrShortDst
|
|
break
|
|
}
|
|
r = rune(src[nSrc])
|
|
|
|
// Decode a 1-byte rune.
|
|
if r < utf8.RuneSelf {
|
|
if m.charmap.asciiSuperset {
|
|
nSrc++
|
|
dst[nDst] = uint8(r)
|
|
nDst++
|
|
continue
|
|
}
|
|
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
|
|
} else {
|
|
err = internal.RepertoireError(m.charmap.replacement)
|
|
}
|
|
break
|
|
}
|
|
}
|
|
|
|
// Binary search in [low, high) for that rune in the m.charmap.encode table.
|
|
for low, high := int(m.charmap.low), 0x100; ; {
|
|
if low >= high {
|
|
err = internal.RepertoireError(m.charmap.replacement)
|
|
break loop
|
|
}
|
|
mid := (low + high) / 2
|
|
got := m.charmap.encode[mid]
|
|
gotRune := rune(got & (1<<24 - 1))
|
|
if gotRune < r {
|
|
low = mid + 1
|
|
} else if gotRune > r {
|
|
high = mid
|
|
} else {
|
|
dst[nDst] = byte(got >> 24)
|
|
nDst++
|
|
break
|
|
}
|
|
}
|
|
nSrc += size
|
|
}
|
|
return nDst, nSrc, err
|
|
}
|
|
|
|
// EncodeRune returns the Charmap's byte encoding of the rune r. ok is whether
|
|
// r is in the Charmap's repertoire. If not, b is set to the Charmap's
|
|
// replacement byte. This is often the ASCII substitute character '\x1a'.
|
|
func (m *Charmap) EncodeRune(r rune) (b byte, ok bool) {
|
|
if r < utf8.RuneSelf && m.asciiSuperset {
|
|
return byte(r), true
|
|
}
|
|
for low, high := int(m.low), 0x100; ; {
|
|
if low >= high {
|
|
return m.replacement, false
|
|
}
|
|
mid := (low + high) / 2
|
|
got := m.encode[mid]
|
|
gotRune := rune(got & (1<<24 - 1))
|
|
if gotRune < r {
|
|
low = mid + 1
|
|
} else if gotRune > r {
|
|
high = mid
|
|
} else {
|
|
return byte(got >> 24), true
|
|
}
|
|
}
|
|
}
|