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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
#
#
# Nim's Runtime Library
# (c) Copyright 2012 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
# Nim support for C/C++'s `wide strings`:idx:. This is part of the system
# module! Do not import it directly!
when not declared(NimString):
{.error: "You must not import this module explicitly".}
type
Utf16Char* = distinct int16
WideCString* = ref UncheckedArray[Utf16Char]
{.deprecated: [TUtf16Char: Utf16Char].}
proc len*(w: WideCString): int =
## returns the length of a widestring. This traverses the whole string to
## find the binary zero end marker!
while int16(w[result]) != 0'i16: inc result
const
UNI_REPLACEMENT_CHAR = Utf16Char(0xFFFD'i16)
UNI_MAX_BMP = 0x0000FFFF
UNI_MAX_UTF16 = 0x0010FFFF
UNI_MAX_UTF32 = 0x7FFFFFFF
UNI_MAX_LEGAL_UTF32 = 0x0010FFFF
halfShift = 10
halfBase = 0x0010000
halfMask = 0x3FF
UNI_SUR_HIGH_START = 0xD800
UNI_SUR_HIGH_END = 0xDBFF
UNI_SUR_LOW_START = 0xDC00
UNI_SUR_LOW_END = 0xDFFF
UNI_REPL = 0xFFFD
template ones(n: untyped): untyped = ((1 shl n)-1)
template fastRuneAt(s: cstring, i, L: int, result: untyped, doInc = true) =
## Returns the unicode character ``s[i]`` in `result`. If ``doInc == true``
## `i` is incremented by the number of bytes that have been processed.
bind ones
if ord(s[i]) <=% 127:
result = ord(s[i])
when doInc: inc(i)
elif ord(s[i]) shr 5 == 0b110:
#assert(ord(s[i+1]) shr 6 == 0b10)
if i <= L - 2:
result = (ord(s[i]) and (ones(5))) shl 6 or (ord(s[i+1]) and ones(6))
when doInc: inc(i, 2)
else:
result = UNI_REPL
when doInc: inc(i)
elif ord(s[i]) shr 4 == 0b1110:
if i <= L - 3:
#assert(ord(s[i+1]) shr 6 == 0b10)
#assert(ord(s[i+2]) shr 6 == 0b10)
result = (ord(s[i]) and ones(4)) shl 12 or
(ord(s[i+1]) and ones(6)) shl 6 or
(ord(s[i+2]) and ones(6))
when doInc: inc(i, 3)
else:
result = UNI_REPL
when doInc: inc(i)
elif ord(s[i]) shr 3 == 0b11110:
if i <= L - 4:
#assert(ord(s[i+1]) shr 6 == 0b10)
#assert(ord(s[i+2]) shr 6 == 0b10)
#assert(ord(s[i+3]) shr 6 == 0b10)
result = (ord(s[i]) and ones(3)) shl 18 or
(ord(s[i+1]) and ones(6)) shl 12 or
(ord(s[i+2]) and ones(6)) shl 6 or
(ord(s[i+3]) and ones(6))
when doInc: inc(i, 4)
else:
result = UNI_REPL
when doInc: inc(i)
else:
result = 0xFFFD
when doInc: inc(i)
iterator runes(s: cstring, L: int): int =
var
i = 0
result: int
while i < L:
fastRuneAt(s, i, L, result, true)
yield result
proc newWideCString*(source: cstring, L: int): WideCString =
unsafeNew(result, L * 4 + 2)
#result = cast[wideCString](alloc(L * 4 + 2))
var d = 0
for ch in runes(source, L):
if ch <=% UNI_MAX_BMP:
if ch >=% UNI_SUR_HIGH_START and ch <=% UNI_SUR_LOW_END:
result[d] = UNI_REPLACEMENT_CHAR
else:
result[d] = Utf16Char(toU16(ch))
elif ch >% UNI_MAX_UTF16:
result[d] = UNI_REPLACEMENT_CHAR
else:
let ch = ch -% halfBase
result[d] = Utf16Char(toU16((ch shr halfShift) +% UNI_SUR_HIGH_START))
inc d
result[d] = Utf16Char(toU16((ch and halfMask) +% UNI_SUR_LOW_START))
inc d
result[d] = Utf16Char(0'i16)
proc newWideCString*(s: cstring): WideCString =
if s.isNil: return nil
result = newWideCString(s, s.len)
proc newWideCString*(s: string): WideCString =
result = newWideCString(s, s.len)
proc `$`*(w: WideCString, estimate: int, replacement: int = 0xFFFD): string =
result = newStringOfCap(estimate + estimate shr 2)
var i = 0
while w[i].int16 != 0'i16:
var ch = int(cast[uint16](w[i]))
inc i
if ch >= UNI_SUR_HIGH_START and ch <= UNI_SUR_HIGH_END:
# If the 16 bits following the high surrogate are in the source buffer...
let ch2 = int(cast[uint16](w[i]))
# If it's a low surrogate, convert to UTF32:
if ch2 >= UNI_SUR_LOW_START and ch2 <= UNI_SUR_LOW_END:
ch = (((ch and halfMask) shl halfShift) + (ch2 and halfMask)) + halfBase
inc i
else:
#invalid UTF-16
ch = replacement
elif ch >= UNI_SUR_LOW_START and ch <= UNI_SUR_LOW_END:
#invalid UTF-16
ch = replacement
if ch < 0x80:
result.add chr(ch)
elif ch < 0x800:
result.add chr((ch shr 6) or 0xc0)
result.add chr((ch and 0x3f) or 0x80)
elif ch < 0x10000:
result.add chr((ch shr 12) or 0xe0)
result.add chr(((ch shr 6) and 0x3f) or 0x80)
result.add chr((ch and 0x3f) or 0x80)
elif ch <= 0x10FFFF:
result.add chr((ch shr 18) or 0xf0)
result.add chr(((ch shr 12) and 0x3f) or 0x80)
result.add chr(((ch shr 6) and 0x3f) or 0x80)
result.add chr((ch and 0x3f) or 0x80)
else:
# replacement char(in case user give very large number):
result.add chr(0xFFFD shr 12 or 0b1110_0000)
result.add chr(0xFFFD shr 6 and ones(6) or 0b10_0000_00)
result.add chr(0xFFFD and ones(6) or 0b10_0000_00)
proc `$`*(s: WideCString): string =
result = s $ 80
|