[project @ 2005-07-19 16:44:50 by simonpj]

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

diff --git a/ghc/compiler/utils/FastString.lhs b/ghc/compiler/utils/FastString.lhs
index d46b775..661b89e 100644 (file)
--- a/ghc/compiler/utils/FastString.lhs
+++ b/ghc/compiler/utils/FastString.lhs
@@ -3,8 +3,18 @@
 %
 \section{Fast strings}
 
-Compact representations of character strings with
-unique identifiers (hash-cons'ish).
+FastString:    A compact, hash-consed, representation of character strings.
+               Comparison is O(1), and you can get a Unique from them.
+               Generated by the FSLIT macro
+               Turn into SDoc with Outputable.ftext
+
+LitString:     Just a wrapper for the Addr# of a C string (Ptr CChar).
+               Practically no operations
+               Outputing them is fast
+               Generated by the SLIT macro
+               Turn into SDoc with Outputable.ptext
+
+Use LitString unless you want the facilities of FastString
 
 \begin{code}
 module FastString
@@ -432,8 +442,10 @@ cmpFS (FastString u1# l1# b1#) (FastString u2# l2# b2#) =
     else                   GT
     ))
 
-foreign import ccall "ghc_memcmp" unsafe 
+#ifndef __HADDOCK__
+foreign import ccall unsafe "ghc_memcmp" 
   memcmp :: ByteArray# -> ByteArray# -> Int# -> IO Int
+#endif
 
 -- -----------------------------------------------------------------------------
 -- Outputting 'FastString's
@@ -498,7 +510,6 @@ hPutFS handle (UnicodeStr _ is)
 -- LitStrings, here for convenience only.
 
 type LitString = Ptr ()
--- ToDo: make it a Ptr when we don't have to support 4.08 any more
 
 mkLitString# :: Addr# -> LitString
 mkLitString# a# = Ptr a#