[commit: ghc] master: Redefine appendFS in terms of appendFB (2f01deb)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/2f01debc33a3ba60feaf2f9add0778bbd2ab81c2

>---------------------------------------------------------------

commit 2f01debc33a3ba60feaf2f9add0778bbd2ab81c2
Author: Ian Lynagh <igloo at earth.li>
Date:   Sat Jul 14 22:11:14 2012 +0100

    Redefine appendFS in terms of appendFB
    
    I think the old definition had a bug, although it probably never
    actually bit us: It used lengthFS to work out how large the arguments
    where, but lengthFS returns the number of characters, not bytes.

>---------------------------------------------------------------

 compiler/utils/FastString.lhs |   16 ++++------------
 1 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/compiler/utils/FastString.lhs b/compiler/utils/FastString.lhs
index a340e6e..29965b1 100644
--- a/compiler/utils/FastString.lhs
+++ b/compiler/utils/FastString.lhs
@@ -540,18 +540,10 @@ zEncodeFS fs@(FastString _ _ _ _ enc) =
             return efs
 
 appendFS :: FastString -> FastString -> FastString
-appendFS fs1 fs2 =
-  inlinePerformIO $ do
-    r <- mallocForeignPtrBytes len
-    withForeignPtr r $ \ r' -> do
-    withForeignPtr (buf fs1) $ \ fs1Ptr -> do
-    withForeignPtr (buf fs2) $ \ fs2Ptr -> do
-        copyBytes r' fs1Ptr len1
-        copyBytes (advancePtr r' len1) fs2Ptr len2
-        mkFastStringForeignPtr r' r len
-  where len  = len1 + len2
-        len1 = lengthFS fs1
-        len2 = lengthFS fs2
+appendFS fs1 fs2 = inlinePerformIO
+                 $ mkFastStringFastBytes
+                 $ appendFB (fastStringToFastBytes fs1)
+                            (fastStringToFastBytes fs2)
 
 concatFS :: [FastString] -> FastString
 concatFS ls = mkFastString (Prelude.concat (map unpackFS ls)) -- ToDo: do better