1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
package charset
import (
"fmt"
"unicode/utf8"
)
func init() {
registerClass("big5", fromBig5, nil)
}
// Big5 consists of 89 fonts of 157 chars each
const (
big5Max = 13973
big5Font = 157
big5Data = "big5.dat"
)
type translateFromBig5 struct {
font int
scratch []byte
big5map []rune
}
func (p *translateFromBig5) Translate(data []byte, eof bool) (int, []byte, error) {
p.scratch = p.scratch[:0]
n := 0
for len(data) > 0 {
c := int(data[0])
data = data[1:]
n++
if p.font == -1 {
// idle state
if c >= 0xa1 {
p.font = c
continue
}
if c == 26 {
c = '\n'
}
continue
}
f := p.font
p.font = -1
r := utf8.RuneError
switch {
case c >= 64 && c <= 126:
c -= 64
case c >= 161 && c <= 254:
c = c - 161 + 63
default:
// bad big5 char
f = 255
}
if f <= 254 {
f -= 161
ix := f*big5Font + c
if ix < len(p.big5map) {
r = p.big5map[ix]
}
if r == -1 {
r = utf8.RuneError
}
}
p.scratch = appendRune(p.scratch, r)
}
return n, p.scratch, nil
}
type big5Key bool
func fromBig5(arg string) (Translator, error) {
big5map, err := cache(big5Key(false), func() (interface{}, error) {
data, err := readFile(big5Data)
if err != nil {
return nil, fmt.Errorf("charset: cannot open big5 data file: %v", err)
}
big5map := []rune(string(data))
if len(big5map) != big5Max {
return nil, fmt.Errorf("charset: corrupt big5 data")
}
return big5map, nil
})
if err != nil {
return nil, err
}
return &translateFromBig5{big5map: big5map.([]rune), font: -1}, nil
}
|
