use the native unicode support from GHC 6.12

src/compiler/GF/Text/Coding.hs

@@ -1,24 +1,69 @@
 module GF.Text.Coding where
 
-import GF.Infra.Option
-import GF.Text.UTF8
-import GF.Text.CP1250
-import GF.Text.CP1251
-import GF.Text.CP1252
-import GF.Text.CP1254
+import qualified Data.ByteString as BS
+import Data.ByteString.Internal
+import GHC.IO
+import GHC.IO.Buffer
+import GHC.IO.Encoding
+import GHC.IO.Exception
+import Control.Monad
 
-encodeUnicode e = case e of
-  UTF_8   -> encodeUTF8
-  CP_1250 -> encodeCP1250
-  CP_1251 -> encodeCP1251
-  CP_1252 -> encodeCP1252
-  CP_1254 -> encodeCP1254
-  _       -> id
+encodeUnicode :: TextEncoding -> String -> ByteString
+encodeUnicode enc s =
+  unsafePerformIO $ do
+    let len = length s
+    cbuf0 <- newCharBuffer (len*4) ReadBuffer
+    foldM (\i c -> writeCharBuf (bufRaw cbuf0) i c) 0 s
+    let cbuf = cbuf0{bufR=len}
+    case enc of
+      TextEncoding {mkTextEncoder=mk} -> do encoder <- mk
+                                            bss <- translate (encode encoder) cbuf
+                                            close encoder
+                                            return (BS.concat bss)
+  where
+    translate cod cbuf
+      | i < w     = do bbuf <- newByteBuffer 128 WriteBuffer
+                       (cbuf,bbuf) <- cod cbuf bbuf
+                       if isEmptyBuffer bbuf
+                         then ioe_invalidCharacter
+                         else do let bs = PS (bufRaw bbuf) (bufL bbuf) (bufR bbuf-bufL bbuf)
+                                 bss <- translate cod cbuf
+                                 return (bs:bss)
+      | otherwise = return []
+      where
+        i = bufL cbuf
+        w = bufR cbuf
 
-decodeUnicode e = case e of
-  UTF_8   -> decodeUTF8
-  CP_1250 -> decodeCP1250
-  CP_1251 -> decodeCP1251
-  CP_1252 -> decodeCP1252
-  CP_1254 -> decodeCP1254
-  _       -> id
+decodeUnicode :: TextEncoding -> ByteString -> String
+decodeUnicode enc (PS fptr l len) =
+  unsafePerformIO $ do
+    let bbuf = Buffer{bufRaw=fptr, bufState=ReadBuffer, bufSize=len, bufL=l, bufR=l+len}
+    cbuf <- newCharBuffer 128 WriteBuffer
+    case enc of
+      TextEncoding {mkTextDecoder=mk} -> do decoder <- mk
+                                            s <- translate (encode decoder) bbuf cbuf
+                                            close decoder
+                                            return s
+  where
+    translate cod bbuf cbuf
+      | i < w     = do (bbuf,cbuf) <- cod bbuf cbuf
+                       if isEmptyBuffer cbuf
+                         then ioe_invalidCharacter
+                         else unpack cod bbuf cbuf
+      | otherwise = return []
+      where
+        i = bufL bbuf
+        w = bufR bbuf
+                                            
+    unpack cod bbuf cbuf
+      | i < w     = do (c,i') <- readCharBuf (bufRaw cbuf) i
+                       cs <- unpack cod bbuf cbuf{bufL=i'}
+                       return (c:cs)
+      | otherwise = translate cod bbuf cbuf{bufL=0,bufR=0}
+      where
+        i = bufL cbuf
+        w = bufR cbuf
+
+ioe_invalidCharacter = ioException
+   (IOError Nothing InvalidArgument ""
+        ("invalid byte sequence for this encoding") Nothing Nothing)