[project @ 2002-09-13 15:02:25 by simonpj]

[ghc-hetmet.git] / ghc / compiler / hsSyn / HsImpExp.lhs

diff --git a/ghc/compiler/hsSyn/HsImpExp.lhs b/ghc/compiler/hsSyn/HsImpExp.lhs
index b33fb2b..52ce08b 100644 (file)
--- a/ghc/compiler/hsSyn/HsImpExp.lhs
+++ b/ghc/compiler/hsSyn/HsImpExp.lhs
@@ -8,11 +8,11 @@ module HsImpExp where
 
 #include "HsVersions.h"
 
-import Name            ( isLexSym )
-import Module          ( ModuleName, WhereFrom )
+import Module          ( ModuleName )
 import Outputable
 import FastString
 import SrcLoc          ( SrcLoc )
+import Char            ( isAlpha )
 \end{code}
 
 %************************************************************************
@@ -25,7 +25,7 @@ One per \tr{import} declaration in a module.
 \begin{code}
 data ImportDecl name
   = ImportDecl   ModuleName                    -- module name
-                 WhereFrom
+                 Bool                          -- True <=> {-# SOURCE #-} import
                  Bool                          -- True => qualified
                  (Maybe ModuleName)            -- as Module
                  (Maybe (Bool, [IE name]))     -- (True => hiding, names)
@@ -35,7 +35,7 @@ data ImportDecl name
 \begin{code}
 instance (Outputable name) => Outputable (ImportDecl name) where
     ppr (ImportDecl mod from qual as spec _)
-      = hang (hsep [ptext SLIT("import"), ppr from, 
+      = hang (hsep [ptext SLIT("import"), ppr_imp from, 
                     pp_qual qual, ppr mod, pp_as as])
             4 (pp_spec spec)
       where
@@ -45,6 +45,9 @@ instance (Outputable name) => Outputable (ImportDecl name) where
        pp_as Nothing   = empty
        pp_as (Just a)  = ptext SLIT("as ") <+> ppr a
 
+       ppr_imp True  = ptext SLIT("{-# SOURCE #-}")
+       ppr_imp False = empty
+
        pp_spec Nothing = empty
        pp_spec (Just (False, spec))
                        = parens (interpp'SP spec)
@@ -86,23 +89,33 @@ ieNames (IEModuleContents _   ) = []
 
 \begin{code}
 instance (Outputable name) => Outputable (IE name) where
-    ppr (IEVar         var)    = ppr_var var
+    ppr (IEVar         var)    = pprHsVar var
     ppr (IEThingAbs    thing)  = ppr thing
     ppr (IEThingAll    thing)  = hcat [ppr thing, text "(..)"]
     ppr (IEThingWith thing withs)
-       = ppr thing <> parens (fsep (punctuate comma (map ppr_var withs)))
+       = ppr thing <> parens (fsep (punctuate comma (map pprHsVar withs)))
     ppr (IEModuleContents mod)
        = ptext SLIT("module") <+> ppr mod
-
-ppr_var v | isOperator v = parens (ppr v)
-         | otherwise    = ppr v
 \end{code}
 
 \begin{code}
-isOperator :: Outputable a => a -> Bool
-isOperator v = isLexSym (mkFastString (showSDocUnqual (ppr v)))
-       -- We use (showSDoc (ppr v)), rather than isSymOcc (getOccName v) simply so
-       -- that we don't need NamedThing in the context of all these functions.
-       -- Gruesome, but simple.
+pprHsVar :: Outputable name => name -> SDoc
+pprHsVar v | isOperator ppr_v = parens ppr_v
+          | otherwise        = ppr_v
+          where
+            ppr_v = ppr v
+
+isOperator :: SDoc -> Bool
+isOperator ppr_v 
+  = case showSDocUnqual ppr_v of
+       ('(':s)   -> False              -- (), (,) etc
+       ('[':s)   -> False              -- []
+       ('$':c:s) -> not (isAlpha c)    -- Don't treat $d as an operator
+       (':':c:s) -> not (isAlpha c)    -- Don't treat :T as an operator
+       (c:s)     -> not (isAlpha c)    -- Starts with non-alpha
+       other     -> False
+    -- We use (showSDoc (ppr v)), rather than isSymOcc (getOccName v) simply so
+    -- that we don't need NamedThing in the context of all these functions.
+    -- Gruesome, but simple.
 \end{code}