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 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 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 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 writeCharBuf oraw ow (chr4 c0 c1 c2 c3)
95 invalid = if ir > ir0 then done ir ow else ioe_decodingError
97 -- lambda-lifted, to avoid thunks being built in the inner-loop:
98 done !ir !ow = return (if ir == iw then input{ bufL=0, bufR=0 }
99 else input{ bufL=ir },
104 ioe_decodingError :: IO a
105 ioe_decodingError = ioException
106 (IOError Nothing InvalidArgument "utf8_decode"
107 "invalid UTF-8 byte sequence" Nothing Nothing)
109 utf8_encode :: EncodeBuffer
111 input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
112 output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
114 done !ir !ow = return (if ir == iw then input{ bufL=0, bufR=0 }
115 else input{ bufL=ir },
118 | ow >= os || ir >= iw = done ir ow
120 (c,ir') <- readCharBuf iraw ir
123 writeWord8Buf oraw ow (fromIntegral x)
126 if os - ow < 2 then done ir ow else do
128 writeWord8Buf oraw ow c1
129 writeWord8Buf oraw (ow+1) c2
132 if os - ow < 3 then done ir ow else do
133 let (c1,c2,c3) = ord3 c
134 writeWord8Buf oraw ow c1
135 writeWord8Buf oraw (ow+1) c2
136 writeWord8Buf oraw (ow+2) c3
139 if os - ow < 4 then done ir ow else do
140 let (c1,c2,c3,c4) = ord4 c
141 writeWord8Buf oraw ow c1
142 writeWord8Buf oraw (ow+1) c2
143 writeWord8Buf oraw (ow+2) c3
144 writeWord8Buf oraw (ow+3) c4
149 -- -----------------------------------------------------------------------------
150 -- UTF-8 primitives, lifted from Data.Text.Fusion.Utf8
152 ord2 :: Char -> (Word8,Word8)
153 ord2 c = assert (n >= 0x80 && n <= 0x07ff) (x1,x2)
156 x1 = fromIntegral $ (n `shiftR` 6) + 0xC0
157 x2 = fromIntegral $ (n .&. 0x3F) + 0x80
159 ord3 :: Char -> (Word8,Word8,Word8)
160 ord3 c = assert (n >= 0x0800 && n <= 0xffff) (x1,x2,x3)
163 x1 = fromIntegral $ (n `shiftR` 12) + 0xE0
164 x2 = fromIntegral $ ((n `shiftR` 6) .&. 0x3F) + 0x80
165 x3 = fromIntegral $ (n .&. 0x3F) + 0x80
167 ord4 :: Char -> (Word8,Word8,Word8,Word8)
168 ord4 c = assert (n >= 0x10000) (x1,x2,x3,x4)
171 x1 = fromIntegral $ (n `shiftR` 18) + 0xF0
172 x2 = fromIntegral $ ((n `shiftR` 12) .&. 0x3F) + 0x80
173 x3 = fromIntegral $ ((n `shiftR` 6) .&. 0x3F) + 0x80
174 x4 = fromIntegral $ (n .&. 0x3F) + 0x80
176 chr2 :: Word8 -> Word8 -> Char
177 chr2 (W8# x1#) (W8# x2#) = C# (chr# (z1# +# z2#))
181 !z1# = uncheckedIShiftL# (y1# -# 0xC0#) 6#
185 chr3 :: Word8 -> Word8 -> Word8 -> Char
186 chr3 (W8# x1#) (W8# x2#) (W8# x3#) = C# (chr# (z1# +# z2# +# z3#))
191 !z1# = uncheckedIShiftL# (y1# -# 0xE0#) 12#
192 !z2# = uncheckedIShiftL# (y2# -# 0x80#) 6#
196 chr4 :: Word8 -> Word8 -> Word8 -> Word8 -> Char
197 chr4 (W8# x1#) (W8# x2#) (W8# x3#) (W8# x4#) =
198 C# (chr# (z1# +# z2# +# z3# +# z4#))
204 !z1# = uncheckedIShiftL# (y1# -# 0xF0#) 18#
205 !z2# = uncheckedIShiftL# (y2# -# 0x80#) 12#
206 !z3# = uncheckedIShiftL# (y3# -# 0x80#) 6#
210 between :: Word8 -- ^ byte to check
211 -> Word8 -- ^ lower bound
212 -> Word8 -- ^ upper bound
214 between x y z = x >= y && x <= z
215 {-# INLINE between #-}
217 validate3 :: Word8 -> Word8 -> Word8 -> Bool
218 {-# INLINE validate3 #-}
219 validate3 x1 x2 x3 = validate3_1 ||
224 validate3_1 = (x1 == 0xE0) &&
225 between x2 0xA0 0xBF &&
227 validate3_2 = between x1 0xE1 0xEC &&
228 between x2 0x80 0xBF &&
230 validate3_3 = x1 == 0xED &&
231 between x2 0x80 0x9F &&
233 validate3_4 = between x1 0xEE 0xEF &&
234 between x2 0x80 0xBF &&
237 validate4 :: Word8 -> Word8 -> Word8 -> Word8 -> Bool
238 {-# INLINE validate4 #-}
239 validate4 x1 x2 x3 x4 = validate4_1 ||
243 validate4_1 = x1 == 0xF0 &&
244 between x2 0x90 0xBF &&
245 between x3 0x80 0xBF &&
247 validate4_2 = between x1 0xF1 0xF3 &&
248 between x2 0x80 0xBF &&
249 between x3 0x80 0xBF &&
251 validate4_3 = x1 == 0xF4 &&
252 between x2 0x80 0x8F &&
253 between x3 0x80 0xBF &&