1 {-# OPTIONS_GHC -fno-implicit-prelude -funbox-strict-fields #-}
2 {-# LANGUAGE BangPatterns #-}
3 -----------------------------------------------------------------------------
5 -- Module : GHC.IO.Encoding.UTF8
6 -- Copyright : (c) The University of Glasgow, 2009
7 -- License : see libraries/base/LICENSE
9 -- Maintainer : libraries@haskell.org
10 -- Stability : internal
11 -- Portability : non-portable
13 -- UTF-8 Codec for the IO library
15 -- Portions Copyright : (c) Tom Harper 2008-2009,
16 -- (c) Bryan O'Sullivan 2009,
17 -- (c) Duncan Coutts 2009
19 -----------------------------------------------------------------------------
21 module GHC.IO.Encoding.UTF8 (
31 import GHC.IO.Exception
33 import GHC.IO.Encoding.Types
39 utf8 = TextEncoding { mkTextDecoder = utf8_DF,
40 mkTextEncoder = utf8_EF }
42 utf8_DF :: IO (TextDecoder ())
48 setState = const $ return ()
51 utf8_EF :: IO (TextEncoder ())
57 setState = const $ return ()
60 utf8_decode :: DecodeBuffer
62 input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
63 output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
66 | ow >= os || ir >= iw = done ir ow
68 c0 <- readWord8Buf iraw ir
71 ow' <- writeCharBuf oraw ow (unsafeChr (fromIntegral c0))
73 | c0 >= 0xc0 && c0 <= 0xdf ->
74 if iw - ir < 2 then done ir ow else do
75 c1 <- readWord8Buf iraw (ir+1)
76 if (c1 < 0x80 || c1 >= 0xc0) then invalid else do
77 ow' <- writeCharBuf oraw ow (chr2 c0 c1)
79 | c0 >= 0xe0 && c0 <= 0xef ->
80 if iw - ir < 3 then done ir ow else do
81 c1 <- readWord8Buf iraw (ir+1)
82 c2 <- readWord8Buf iraw (ir+2)
83 if not (validate3 c0 c1 c2) then invalid else do
84 ow' <- writeCharBuf oraw ow (chr3 c0 c1 c2)
87 if iw - ir < 4 then done ir ow else do
88 c1 <- readWord8Buf iraw (ir+1)
89 c2 <- readWord8Buf iraw (ir+2)
90 c3 <- readWord8Buf iraw (ir+3)
91 if not (validate4 c0 c1 c2 c3) then invalid else do
92 ow' <- writeCharBuf oraw ow (chr4 c0 c1 c2 c3)
97 invalid = if ir > ir0 then done ir ow else ioe_decodingError
99 -- lambda-lifted, to avoid thunks being built in the inner-loop:
100 done !ir !ow = return (if ir == iw then input{ bufL=0, bufR=0 }
101 else input{ bufL=ir },
106 ioe_decodingError :: IO a
107 ioe_decodingError = ioException
108 (IOError Nothing InvalidArgument "utf8_decode"
109 "invalid UTF-8 byte sequence" Nothing Nothing)
111 utf8_encode :: EncodeBuffer
113 input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
114 output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
116 done !ir !ow = return (if ir == iw then input{ bufL=0, bufR=0 }
117 else input{ bufL=ir },
120 | ow >= os || ir >= iw = done ir ow
122 (c,ir') <- readCharBuf iraw ir
125 writeWord8Buf oraw ow (fromIntegral x)
128 if os - ow < 2 then done ir ow else do
130 writeWord8Buf oraw ow c1
131 writeWord8Buf oraw (ow+1) c2
134 if os - ow < 3 then done ir ow else do
135 let (c1,c2,c3) = ord3 c
136 writeWord8Buf oraw ow c1
137 writeWord8Buf oraw (ow+1) c2
138 writeWord8Buf oraw (ow+2) c3
141 if os - ow < 4 then done ir ow else do
142 let (c1,c2,c3,c4) = ord4 c
143 writeWord8Buf oraw ow c1
144 writeWord8Buf oraw (ow+1) c2
145 writeWord8Buf oraw (ow+2) c3
146 writeWord8Buf oraw (ow+3) c4
151 -- -----------------------------------------------------------------------------
152 -- UTF-8 primitives, lifted from Data.Text.Fusion.Utf8
154 ord2 :: Char -> (Word8,Word8)
155 ord2 c = assert (n >= 0x80 && n <= 0x07ff) (x1,x2)
158 x1 = fromIntegral $ (n `shiftR` 6) + 0xC0
159 x2 = fromIntegral $ (n .&. 0x3F) + 0x80
161 ord3 :: Char -> (Word8,Word8,Word8)
162 ord3 c = assert (n >= 0x0800 && n <= 0xffff) (x1,x2,x3)
165 x1 = fromIntegral $ (n `shiftR` 12) + 0xE0
166 x2 = fromIntegral $ ((n `shiftR` 6) .&. 0x3F) + 0x80
167 x3 = fromIntegral $ (n .&. 0x3F) + 0x80
169 ord4 :: Char -> (Word8,Word8,Word8,Word8)
170 ord4 c = assert (n >= 0x10000) (x1,x2,x3,x4)
173 x1 = fromIntegral $ (n `shiftR` 18) + 0xF0
174 x2 = fromIntegral $ ((n `shiftR` 12) .&. 0x3F) + 0x80
175 x3 = fromIntegral $ ((n `shiftR` 6) .&. 0x3F) + 0x80
176 x4 = fromIntegral $ (n .&. 0x3F) + 0x80
178 chr2 :: Word8 -> Word8 -> Char
179 chr2 (W8# x1#) (W8# x2#) = C# (chr# (z1# +# z2#))
183 !z1# = uncheckedIShiftL# (y1# -# 0xC0#) 6#
187 chr3 :: Word8 -> Word8 -> Word8 -> Char
188 chr3 (W8# x1#) (W8# x2#) (W8# x3#) = C# (chr# (z1# +# z2# +# z3#))
193 !z1# = uncheckedIShiftL# (y1# -# 0xE0#) 12#
194 !z2# = uncheckedIShiftL# (y2# -# 0x80#) 6#
198 chr4 :: Word8 -> Word8 -> Word8 -> Word8 -> Char
199 chr4 (W8# x1#) (W8# x2#) (W8# x3#) (W8# x4#) =
200 C# (chr# (z1# +# z2# +# z3# +# z4#))
206 !z1# = uncheckedIShiftL# (y1# -# 0xF0#) 18#
207 !z2# = uncheckedIShiftL# (y2# -# 0x80#) 12#
208 !z3# = uncheckedIShiftL# (y3# -# 0x80#) 6#
212 between :: Word8 -- ^ byte to check
213 -> Word8 -- ^ lower bound
214 -> Word8 -- ^ upper bound
216 between x y z = x >= y && x <= z
217 {-# INLINE between #-}
219 validate3 :: Word8 -> Word8 -> Word8 -> Bool
220 {-# INLINE validate3 #-}
221 validate3 x1 x2 x3 = validate3_1 ||
226 validate3_1 = (x1 == 0xE0) &&
227 between x2 0xA0 0xBF &&
229 validate3_2 = between x1 0xE1 0xEC &&
230 between x2 0x80 0xBF &&
232 validate3_3 = x1 == 0xED &&
233 between x2 0x80 0x9F &&
235 validate3_4 = between x1 0xEE 0xEF &&
236 between x2 0x80 0xBF &&
239 validate4 :: Word8 -> Word8 -> Word8 -> Word8 -> Bool
240 {-# INLINE validate4 #-}
241 validate4 x1 x2 x3 x4 = validate4_1 ||
245 validate4_1 = x1 == 0xF0 &&
246 between x2 0x90 0xBF &&
247 between x3 0x80 0xBF &&
249 validate4_2 = between x1 0xF1 0xF3 &&
250 between x2 0x80 0xBF &&
251 between x3 0x80 0xBF &&
253 validate4_3 = x1 == 0xF4 &&
254 between x2 0x80 0x8F &&
255 between x3 0x80 0xBF &&