forked from inexorabletash/text-encoding
-
Notifications
You must be signed in to change notification settings - Fork 20
Expand file tree
/
Copy pathtext-encoder-lite.js
More file actions
140 lines (122 loc) · 3.29 KB
/
text-encoder-lite.js
File metadata and controls
140 lines (122 loc) · 3.29 KB
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
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
function TextEncoderLite() {
}
function TextDecoderLite() {
}
(function () {
'use strict';
// Taken from https://github.com/feross/buffer/blob/master/index.js
// Thanks Feross et al! :-)
function utf8ToBytes (string, units) {
units = units || Infinity
var codePoint
var length = string.length
var leadSurrogate = null
var bytes = []
var i = 0
for (; i < length; i++) {
codePoint = string.charCodeAt(i)
// is surrogate component
if (codePoint > 0xD7FF && codePoint < 0xE000) {
// last char was a lead
if (leadSurrogate) {
// 2 leads in a row
if (codePoint < 0xDC00) {
if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
leadSurrogate = codePoint
continue
} else {
// valid surrogate pair
codePoint = leadSurrogate - 0xD800 << 10 | codePoint - 0xDC00 | 0x10000
leadSurrogate = null
}
} else {
// no lead yet
if (codePoint > 0xDBFF) {
// unexpected trail
if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
continue
} else if (i + 1 === length) {
// unpaired lead
if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
continue
} else {
// valid lead
leadSurrogate = codePoint
continue
}
}
} else if (leadSurrogate) {
// valid bmp char, but last char was a lead
if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
leadSurrogate = null
}
// encode utf8
if (codePoint < 0x80) {
if ((units -= 1) < 0) break
bytes.push(codePoint)
} else if (codePoint < 0x800) {
if ((units -= 2) < 0) break
bytes.push(
codePoint >> 0x6 | 0xC0,
codePoint & 0x3F | 0x80
)
} else if (codePoint < 0x10000) {
if ((units -= 3) < 0) break
bytes.push(
codePoint >> 0xC | 0xE0,
codePoint >> 0x6 & 0x3F | 0x80,
codePoint & 0x3F | 0x80
)
} else if (codePoint < 0x200000) {
if ((units -= 4) < 0) break
bytes.push(
codePoint >> 0x12 | 0xF0,
codePoint >> 0xC & 0x3F | 0x80,
codePoint >> 0x6 & 0x3F | 0x80,
codePoint & 0x3F | 0x80
)
} else {
throw new Error('Invalid code point')
}
}
return bytes
}
function utf8Slice (buf, start, end) {
var res = ''
var tmp = ''
end = Math.min(buf.length, end || Infinity)
start = start || 0;
for (var i = start; i < end; i++) {
if (buf[i] <= 0x7F) {
res += decodeUtf8Char(tmp) + String.fromCharCode(buf[i])
tmp = ''
} else {
tmp += '%' + buf[i].toString(16)
}
}
return res + decodeUtf8Char(tmp)
}
function decodeUtf8Char (str) {
try {
return dec
479B
odeURIComponent(str)
} catch (err) {
return String.fromCharCode(0xFFFD) // UTF 8 invalid char
}
}
TextEncoderLite.prototype.encode = function (str) {
var result;
if ('undefined' === typeof Uint8Array) {
result = utf8ToBytes(str);
} else {
result = new Uint8Array(utf8ToBytes(str));
}
return result;
};
TextDecoderLite.prototype.decode = function (bytes) {
return utf8Slice(bytes, 0, bytes.length);
}
}());
if(typeof module === "object" && module) {
module.exports.TextDecoderLite = TextDecoderLite;
module.exports.TextEncoderLite = TextEncoderLite;
}