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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
|
{-# LANGUAGE Trustworthy #-}
{-# LANGUAGE NoImplicitPrelude
, BangPatterns
, NondecreasingIndentation
, MagicHash
#-}
{-# OPTIONS_GHC -funbox-strict-fields #-}
-----------------------------------------------------------------------------
-- |
-- Module : GHC.IO.Encoding.UTF16
-- Copyright : (c) The University of Glasgow, 2009
-- License : see libraries/base/LICENSE
--
-- Maintainer : libraries@haskell.org
-- Stability : internal
-- Portability : non-portable
--
-- UTF-16 Codecs for the IO library
--
-- Portions Copyright : (c) Tom Harper 2008-2009,
-- (c) Bryan O'Sullivan 2009,
-- (c) Duncan Coutts 2009
--
-----------------------------------------------------------------------------
module GHC.IO.Encoding.UTF16 (
utf16, mkUTF16,
utf16_decode,
utf16_encode,
utf16be, mkUTF16be,
utf16be_decode,
utf16be_encode,
utf16le, mkUTF16le,
utf16le_decode,
utf16le_encode,
) where
import GHC.Base
import GHC.Real
import GHC.Num
-- import GHC.IO
import GHC.IO.Buffer
import GHC.IO.Encoding.Failure
import GHC.IO.Encoding.Types
import GHC.Word
import Data.Bits
import GHC.IORef
-- -----------------------------------------------------------------------------
-- The UTF-16 codec: either UTF16BE or UTF16LE with a BOM
utf16 :: TextEncoding
utf16 = mkUTF16 ErrorOnCodingFailure
-- | @since 4.4.0.0
mkUTF16 :: CodingFailureMode -> TextEncoding
mkUTF16 cfm = TextEncoding { textEncodingName = "UTF-16",
mkTextDecoder = utf16_DF cfm,
mkTextEncoder = utf16_EF cfm }
utf16_DF :: CodingFailureMode -> IO (TextDecoder (Maybe DecodeBuffer))
utf16_DF cfm = do
seen_bom <- newIORef Nothing
return (BufferCodec {
encode = utf16_decode seen_bom,
recover = recoverDecode cfm,
close = return (),
getState = readIORef seen_bom,
setState = writeIORef seen_bom
})
utf16_EF :: CodingFailureMode -> IO (TextEncoder Bool)
utf16_EF cfm = do
done_bom <- newIORef False
return (BufferCodec {
encode = utf16_encode done_bom,
recover = recoverEncode cfm,
close = return (),
getState = readIORef done_bom,
setState = writeIORef done_bom
})
utf16_encode :: IORef Bool -> EncodeBuffer
utf16_encode done_bom input
output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow, bufSize=os }
= do
b <- readIORef done_bom
if b then utf16_native_encode input output
else if os - ow < 2
then return (OutputUnderflow,input,output)
else do
writeIORef done_bom True
writeWord8Buf oraw ow bom1
writeWord8Buf oraw (ow+1) bom2
utf16_native_encode input output{ bufR = ow+2 }
utf16_decode :: IORef (Maybe DecodeBuffer) -> DecodeBuffer
utf16_decode seen_bom
input@Buffer{ bufRaw=iraw, bufL=ir, bufR=iw, bufSize=_ }
output
= do
mb <- readIORef seen_bom
case mb of
Just decode -> decode input output
Nothing ->
if iw - ir < 2 then return (InputUnderflow,input,output) else do
c0 <- readWord8Buf iraw ir
c1 <- readWord8Buf iraw (ir+1)
case () of
_ | c0 == bomB && c1 == bomL -> do
writeIORef seen_bom (Just utf16be_decode)
utf16be_decode input{ bufL= ir+2 } output
| c0 == bomL && c1 == bomB -> do
writeIORef seen_bom (Just utf16le_decode)
utf16le_decode input{ bufL= ir+2 } output
| otherwise -> do
writeIORef seen_bom (Just utf16_native_decode)
utf16_native_decode input output
bomB, bomL, bom1, bom2 :: Word8
bomB = 0xfe
bomL = 0xff
-- choose UTF-16BE by default for UTF-16 output
utf16_native_decode :: DecodeBuffer
utf16_native_decode = utf16be_decode
utf16_native_encode :: EncodeBuffer
utf16_native_encode = utf16be_encode
bom1 = bomB
bom2 = bomL
-- -----------------------------------------------------------------------------
-- UTF16LE and UTF16BE
utf16be :: TextEncoding
utf16be = mkUTF16be ErrorOnCodingFailure
-- | @since 4.4.0.0
mkUTF16be :: CodingFailureMode -> TextEncoding
mkUTF16be cfm = TextEncoding { textEncodingName = "UTF-16BE",
mkTextDecoder = utf16be_DF cfm,
mkTextEncoder = utf16be_EF cfm }
utf16be_DF :: CodingFailureMode -> IO (TextDecoder ())
utf16be_DF cfm =
return (BufferCodec {
encode = utf16be_decode,
recover = recoverDecode cfm,
close = return (),
getState = return (),
setState = const $ return ()
})
utf16be_EF :: CodingFailureMode -> IO (TextEncoder ())
utf16be_EF cfm =
return (BufferCodec {
encode = utf16be_encode,
recover = recoverEncode cfm,
close = return (),
getState = return (),
setState = const $ return ()
})
utf16le :: TextEncoding
utf16le = mkUTF16le ErrorOnCodingFailure
-- | @since 4.4.0.0
mkUTF16le :: CodingFailureMode -> TextEncoding
mkUTF16le cfm = TextEncoding { textEncodingName = "UTF16-LE",
mkTextDecoder = utf16le_DF cfm,
mkTextEncoder = utf16le_EF cfm }
utf16le_DF :: CodingFailureMode -> IO (TextDecoder ())
utf16le_DF cfm =
return (BufferCodec {
encode = utf16le_decode,
recover = recoverDecode cfm,
close = return (),
getState = return (),
setState = const $ return ()
})
utf16le_EF :: CodingFailureMode -> IO (TextEncoder ())
utf16le_EF cfm =
return (BufferCodec {
encode = utf16le_encode,
recover = recoverEncode cfm,
close = return (),
getState = return (),
setState = const $ return ()
})
utf16be_decode :: DecodeBuffer
utf16be_decode
input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
= let
loop !ir !ow
| ow >= os = done OutputUnderflow ir ow
| ir >= iw = done InputUnderflow ir ow
| ir + 1 == iw = done InputUnderflow ir ow
| otherwise = do
c0 <- readWord8Buf iraw ir
c1 <- readWord8Buf iraw (ir+1)
let x1 = fromIntegral c0 `shiftL` 8 + fromIntegral c1
if validate1 x1
then do ow' <- writeCharBuf oraw ow (unsafeChr (fromIntegral x1))
loop (ir+2) ow'
else if iw - ir < 4 then done InputUnderflow ir ow else do
c2 <- readWord8Buf iraw (ir+2)
c3 <- readWord8Buf iraw (ir+3)
let x2 = fromIntegral c2 `shiftL` 8 + fromIntegral c3
if not (validate2 x1 x2) then invalid else do
ow' <- writeCharBuf oraw ow (chr2 x1 x2)
loop (ir+4) ow'
where
invalid = done InvalidSequence ir ow
-- lambda-lifted, to avoid thunks being built in the inner-loop:
done why !ir !ow = return (why,
if ir == iw then input{ bufL=0, bufR=0 }
else input{ bufL=ir },
output{ bufR=ow })
in
loop ir0 ow0
utf16le_decode :: DecodeBuffer
utf16le_decode
input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
= let
loop !ir !ow
| ow >= os = done OutputUnderflow ir ow
| ir >= iw = done InputUnderflow ir ow
| ir + 1 == iw = done InputUnderflow ir ow
| otherwise = do
c0 <- readWord8Buf iraw ir
c1 <- readWord8Buf iraw (ir+1)
let x1 = fromIntegral c1 `shiftL` 8 + fromIntegral c0
if validate1 x1
then do ow' <- writeCharBuf oraw ow (unsafeChr (fromIntegral x1))
loop (ir+2) ow'
else if iw - ir < 4 then done InputUnderflow ir ow else do
c2 <- readWord8Buf iraw (ir+2)
c3 <- readWord8Buf iraw (ir+3)
let x2 = fromIntegral c3 `shiftL` 8 + fromIntegral c2
if not (validate2 x1 x2) then invalid else do
ow' <- writeCharBuf oraw ow (chr2 x1 x2)
loop (ir+4) ow'
where
invalid = done InvalidSequence ir ow
-- lambda-lifted, to avoid thunks being built in the inner-loop:
done why !ir !ow = return (why,
if ir == iw then input{ bufL=0, bufR=0 }
else input{ bufL=ir },
output{ bufR=ow })
in
loop ir0 ow0
utf16be_encode :: EncodeBuffer
utf16be_encode
input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
= let
done why !ir !ow = return (why,
if ir == iw then input{ bufL=0, bufR=0 }
else input{ bufL=ir },
output{ bufR=ow })
loop !ir !ow
| ir >= iw = done InputUnderflow ir ow
| os - ow < 2 = done OutputUnderflow ir ow
| otherwise = do
(c,ir') <- readCharBuf iraw ir
case ord c of
x | x < 0x10000 -> if isSurrogate c then done InvalidSequence ir ow else do
writeWord8Buf oraw ow (fromIntegral (x `shiftR` 8))
writeWord8Buf oraw (ow+1) (fromIntegral x)
loop ir' (ow+2)
| otherwise -> do
if os - ow < 4 then done OutputUnderflow ir ow else do
let
n1 = x - 0x10000
c1 = fromIntegral (n1 `shiftR` 18 + 0xD8)
c2 = fromIntegral (n1 `shiftR` 10)
n2 = n1 .&. 0x3FF
c3 = fromIntegral (n2 `shiftR` 8 + 0xDC)
c4 = fromIntegral n2
--
writeWord8Buf oraw ow c1
writeWord8Buf oraw (ow+1) c2
writeWord8Buf oraw (ow+2) c3
writeWord8Buf oraw (ow+3) c4
loop ir' (ow+4)
in
loop ir0 ow0
utf16le_encode :: EncodeBuffer
utf16le_encode
input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
= let
done why !ir !ow = return (why,
if ir == iw then input{ bufL=0, bufR=0 }
else input{ bufL=ir },
output{ bufR=ow })
loop !ir !ow
| ir >= iw = done InputUnderflow ir ow
| os - ow < 2 = done OutputUnderflow ir ow
| otherwise = do
(c,ir') <- readCharBuf iraw ir
case ord c of
x | x < 0x10000 -> if isSurrogate c then done InvalidSequence ir ow else do
writeWord8Buf oraw ow (fromIntegral x)
writeWord8Buf oraw (ow+1) (fromIntegral (x `shiftR` 8))
loop ir' (ow+2)
| otherwise ->
if os - ow < 4 then done OutputUnderflow ir ow else do
let
n1 = x - 0x10000
c1 = fromIntegral (n1 `shiftR` 18 + 0xD8)
c2 = fromIntegral (n1 `shiftR` 10)
n2 = n1 .&. 0x3FF
c3 = fromIntegral (n2 `shiftR` 8 + 0xDC)
c4 = fromIntegral n2
--
writeWord8Buf oraw ow c2
writeWord8Buf oraw (ow+1) c1
writeWord8Buf oraw (ow+2) c4
writeWord8Buf oraw (ow+3) c3
loop ir' (ow+4)
in
loop ir0 ow0
chr2 :: Word16 -> Word16 -> Char
chr2 (W16# a#) (W16# b#) = C# (chr# (upper# +# lower# +# 0x10000#))
where
!x# = word2Int# a#
!y# = word2Int# b#
!upper# = uncheckedIShiftL# (x# -# 0xD800#) 10#
!lower# = y# -# 0xDC00#
{-# INLINE chr2 #-}
validate1 :: Word16 -> Bool
validate1 x1 = (x1 >= 0 && x1 < 0xD800) || x1 > 0xDFFF
{-# INLINE validate1 #-}
validate2 :: Word16 -> Word16 -> Bool
validate2 x1 x2 = x1 >= 0xD800 && x1 <= 0xDBFF &&
x2 >= 0xDC00 && x2 <= 0xDFFF
{-# INLINE validate2 #-}
|
