[project @ 2002-04-29 16:17:55 by simonmar]

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

diff --git a/ghc/compiler/utils/Pretty.lhs b/ghc/compiler/utils/Pretty.lhs
index 6f4f614..994435a 100644 (file)
--- a/ghc/compiler/utils/Pretty.lhs
+++ b/ghc/compiler/utils/Pretty.lhs
@@ -189,8 +189,21 @@ import IOExts              ( hPutBufFull )
 import System.IO       ( hPutBuf )
 #endif
 
+#if __GLASGOW_HASKELL__ < 503
+import PrelBase                ( unpackCString# )
+#else
+import GHC.Base                ( unpackCString# )
+#endif
+
 import PrimPacked      ( strLength )
 
+#if __GLASGOW_HASKELL__ < 411
+import PrelAddr                ( Addr(..) )
+#else
+import Addr            ( Addr(..) )
+import Ptr             ( Ptr(..) )
+#endif
+
 -- Don't import Util( assertPanic ) because it makes a loop in the module structure
 
 infixl 6 <> 
@@ -595,6 +608,12 @@ text  s = case length   s of {IBOX(sl) -> textBeside_ (Str s)  sl Empty}
 ftext s = case lengthFS s of {IBOX(sl) -> textBeside_ (PStr s) sl Empty}
 ptext (A# s) = case strLength (A# s) of {IBOX(sl) -> textBeside_ (LStr s sl) sl Empty}
 
+-- RULE that turns (text "abc") into (ptext (A# "abc"#)) to avoid the
+-- intermediate packing/unpacking of the string.
+{-# RULES 
+  "text/str" forall a. text (unpackCString# a) = ptext (A# a)
+ #-}
+
 nest IBOX(k)  p = mkNest k (reduceDoc p)        -- Externally callable version
 
 -- mkNest checks for Nest's invariant that it doesn't have an Empty inside it