[project @ 2003-10-07 16:56:33 by sof]

[haskell-directory.git] / Foreign / C / String.hs

diff --git a/Foreign/C/String.hs b/Foreign/C/String.hs
index b7b9bb6..d2d2a29 100644 (file)
--- a/Foreign/C/String.hs
+++ b/Foreign/C/String.hs
@@ -89,10 +89,11 @@ peekCString cp  = do cs <- peekArray0 nUL cp; return (cCharsToChars cs)
 peekCString cp = loop 0
   where
     loop i = do
-        val <- peekElemOff cp i
-        if val == nUL then return [] else do
+        xval <- peekElemOff cp i
+       let val = castCCharToChar xval
+        if (val `seq` (xval == nUL)) then return [] else do
             rest <- loop (i+1)
-            return (castCCharToChar val : rest)
+            return (val : rest)
 #endif
 
 -- marshal a C string with explicit length into a Haskell string 
@@ -101,13 +102,17 @@ peekCStringLen           :: CStringLen -> IO String
 #ifndef __GLASGOW_HASKELL__
 peekCStringLen (cp, len)  = do cs <- peekArray len cp; return (cCharsToChars cs)
 #else
-peekCStringLen (cp, len) = loop 0
+peekCStringLen (cp, len) 
+  | len <= 0  = return "" -- being (too?) nice.
+  | otherwise = loop [] (len-1)
   where
-    loop i | i == len  = return []
-          | otherwise = do
-               val <- peekElemOff cp i
-               rest <- loop (i+1)
-               return (castCCharToChar val : rest)
+    loop acc i = do
+         xval <- peekElemOff cp i
+        let val = castCCharToChar xval
+          -- blow away the coercion ASAP.
+        if (val `seq` (i == 0))
+         then return (val:acc)
+         else loop (val:acc) (i-1)
 #endif
 
 -- marshal a Haskell string into a NUL terminated C strings