More modules that need LANGUAGE BangPatterns

[ghc-hetmet.git] / compiler / utils / StringBuffer.lhs

diff --git a/compiler/utils/StringBuffer.lhs b/compiler/utils/StringBuffer.lhs
index d51c800..5d1bfa6 100644 (file)
--- a/compiler/utils/StringBuffer.lhs
+++ b/compiler/utils/StringBuffer.lhs
@@ -6,6 +6,11 @@
 Buffers for scanning string input stored in external arrays.
 
 \begin{code}
+{-# LANGUAGE BangPatterns #-}
+{-# OPTIONS_GHC -O -funbox-strict-fields #-}
+-- We always optimise this, otherwise performance of a non-optimised
+-- compiler is severely affected
+
 module StringBuffer
        (
         StringBuffer(..),
@@ -75,7 +80,7 @@ data StringBuffer
 instance Show StringBuffer where
         showsPrec _ s = showString "<stringbuffer("
                       . shows (len s) . showString "," . shows (cur s)
-                      . showString ">"
+                      . showString ")>"
 
 -- -----------------------------------------------------------------------------
 -- Creation / Destruction
@@ -134,8 +139,9 @@ appendStringBuffers sb1 sb2
           calcLen sb = len sb - cur sb
           size =  sb1_len + sb2_len
 
-stringToStringBuffer :: String -> IO StringBuffer
-stringToStringBuffer str = do
+stringToStringBuffer :: String -> StringBuffer
+stringToStringBuffer str =
+ unsafePerformIO $ do
   let size = utf8EncodedLength str
   buf <- mallocForeignPtrArray (size+3)
   withForeignPtr buf $ \ptr -> do
@@ -220,7 +226,7 @@ parseUnsignedInteger (StringBuffer buf _ cur) len radix char_to_int
     --LOL, in implementations where the indexing needs slow unsafePerformIO,
     --this is less (not more) efficient than using the IO monad explicitly
     --here.
-    ptr' = pUnbox ptr
+    !ptr' = pUnbox ptr
     byteOff i = cBox (indexWord8OffFastPtrAsFastChar ptr' (iUnbox (cur + i)))
     go i x | i == len  = x
            | otherwise = case byteOff i of