X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Futils%2FOutputable.lhs;h=6d9132e105f2a3bee60c649bebe3e96abab5592a;hb=b98b590f7f62cd8f5c1653584ce37ebf5ac09ffd;hp=ad6548bd62cc1a15be316bbccfbfa4445f42f576;hpb=36f77deda25312534200f10ccdb18528b6ee6e27;p=ghc-hetmet.git

diff --git a/compiler/utils/Outputable.lhs b/compiler/utils/Outputable.lhs
index ad6548b..6d9132e 100644
--- a/compiler/utils/Outputable.lhs
+++ b/compiler/utils/Outputable.lhs
@@ -14,7 +14,8 @@ module Outputable (
 	BindingSite(..),
 
 	PprStyle, CodeStyle(..), PrintUnqualified, alwaysQualify,
-	getPprStyle, withPprStyle, withPprStyleDoc, pprDeeper, pprSetDepth,
+	getPprStyle, withPprStyle, withPprStyleDoc, 
+	pprDeeper, pprDeeperList, pprSetDepth,
 	codeStyle, userStyle, debugStyle, dumpStyle, asmStyle,
 	ifPprDebug, qualName, qualModule,
 	mkErrStyle, defaultErrStyle, defaultDumpStyle, defaultUserStyle,
@@ -188,6 +189,19 @@ pprDeeper d (PprUser q (PartWay 0)) = Pretty.text "..."
 pprDeeper d (PprUser q (PartWay n)) = d (PprUser q (PartWay (n-1)))
 pprDeeper d other_sty        	    = d other_sty
 
+pprDeeperList :: ([SDoc] -> SDoc) -> [SDoc] -> SDoc
+-- Truncate a list that list that is longer than the current depth
+pprDeeperList f ds (PprUser q (PartWay n))
+  | n==0      = Pretty.text "..."
+  | otherwise = f (go 0 ds) (PprUser q (PartWay (n-1)))
+  where
+    go i [] = []
+    go i (d:ds) | i >= n    = [text "...."]
+		| otherwise = d : go (i+1) ds
+
+pprDeeperList f ds other_sty
+  = f ds other_sty
+
 pprSetDepth :: Int -> SDoc -> SDoc
 pprSetDepth n d (PprUser q _) = d (PprUser q (PartWay n))
 pprSetDepth n d other_sty     = d other_sty
@@ -395,6 +409,10 @@ instance Outputable a => Outputable (Maybe a) where
   ppr Nothing = ptext SLIT("Nothing")
   ppr (Just x) = ptext SLIT("Just") <+> ppr x
 
+instance (Outputable a, Outputable b) => Outputable (Either a b) where
+  ppr (Left x)  = ptext SLIT("Left")  <+> ppr x
+  ppr (Right y) = ptext SLIT("Right") <+> ppr y
+
 -- ToDo: may not be used
 instance (Outputable a, Outputable b, Outputable c) => Outputable (a, b, c) where
     ppr (x,y,z) =