[project @ 1996-07-25 20:43:49 by partain]

[ghc-hetmet.git] / ghc / compiler / coreSyn / PprCore.lhs

diff --git a/ghc/compiler/coreSyn/PprCore.lhs b/ghc/compiler/coreSyn/PprCore.lhs
index ed00cac..57945cb 100644 (file)
--- a/ghc/compiler/coreSyn/PprCore.lhs
+++ b/ghc/compiler/coreSyn/PprCore.lhs
@@ -17,25 +17,25 @@ module PprCore (
        pprTypedCoreBinder
        
        -- these are here to make the instances go in 0.26:
-#if __GLASGOW_HASKELL__ <= 26
+#if __GLASGOW_HASKELL__ <= 30
        , GenCoreBinding, GenCoreExpr, GenCoreCaseAlts
        , GenCoreCaseDefault, GenCoreArg
 #endif
     ) where
 
-import Ubiq{-uitous-}
+IMP_Ubiq(){-uitous-}
 
 import CoreSyn
 import CostCentre      ( showCostCentre )
 import Id              ( idType, getIdInfo, getIdStrictness, isTupleCon,
-                         nullIdEnv, DataCon(..), GenId{-instances-}
+                         nullIdEnv, SYN_IE(DataCon), GenId{-instances-}
                        )
 import IdInfo          ( ppIdInfo, StrictnessInfo(..) )
 import Literal         ( Literal{-instances-} )
 import Name            ( isSymLexeme )
 import Outputable      -- quite a few things
 import PprEnv
-import PprType         ( GenType{-instances-}, GenTyVar{-instance-} )
+import PprType         ( pprParendGenType, GenType{-instances-}, GenTyVar{-instance-} )
 import PprStyle                ( PprStyle(..) )
 import Pretty
 import PrimOp          ( PrimOp{-instances-} )
@@ -91,7 +91,7 @@ init_ppr_env sty pbdr1 pbdr2 pocc
        (Just (ppr sty)) -- tyvars
        (Just (ppr sty)) -- usage vars
        (Just pbdr1) (Just pbdr2) (Just pocc) -- value vars
-       (Just (ppr sty)) -- types
+       (Just (pprParendGenType sty)) -- types
        (Just (ppr sty)) -- usages
 
 --------------
@@ -265,6 +265,28 @@ ppr_expr pe expr@(App _ _)
                  ])
 
 ppr_expr pe (Case expr alts)
+  | only_one_alt alts
+    -- johan thinks that single case patterns should be on same line as case,
+    -- and no indent; all sane persons agree with him.
+  = let
+       ppr_alt (AlgAlts  [] (BindDefault n _)) = ppBeside (pMinBndr pe n) (ppStr " ->")
+       ppr_alt (PrimAlts [] (BindDefault n _)) = ppBeside (pMinBndr pe n) (ppStr " ->")
+       ppr_alt (PrimAlts ((l, _):[]) NoDefault)= ppBeside (pLit pe l)     (ppStr " ->")
+       ppr_alt (AlgAlts  ((con, params, _):[]) NoDefault)
+         = ppCat [ppr_alt_con con (pCon pe con),
+                  ppInterleave ppSP (map (pMinBndr pe) params),
+                  ppStr "->"]
+
+       ppr_rhs (AlgAlts [] (BindDefault _ expr))   = ppr_expr pe expr
+       ppr_rhs (AlgAlts ((_,_,expr):[]) NoDefault) = ppr_expr pe expr
+       ppr_rhs (PrimAlts [] (BindDefault _ expr))  = ppr_expr pe expr
+       ppr_rhs (PrimAlts ((_,expr):[]) NoDefault)  = ppr_expr pe expr
+    in 
+    ppSep
+    [ppSep [ppPStr SLIT("case"), ppNest 4 (ppr_parend_expr pe expr), ppStr "of {", ppr_alt alts],
+        ppBeside (ppr_rhs alts) (ppStr "}")]
+
+  | otherwise -- default "case" printing
   = ppSep
     [ppSep [ppPStr SLIT("case"), ppNest 4 (ppr_parend_expr pe expr), ppStr "of {"],
      ppNest 2 (ppr_alts pe alts),
@@ -303,6 +325,15 @@ ppr_expr pe (Coerce c ty expr)
   where
     pp_coerce (CoerceIn  v) = ppBeside (ppStr "{-in-}")  (ppr (pStyle pe) v)
     pp_coerce (CoerceOut v) = ppBeside (ppStr "{-out-}") (ppr (pStyle pe) v)
+
+only_one_alt (AlgAlts []     (BindDefault _ _)) = True
+only_one_alt (AlgAlts (_:[])  NoDefault)       = True
+only_one_alt (PrimAlts []    (BindDefault _ _)) = True
+only_one_alt (PrimAlts (_:[]) NoDefault)       = True
+only_one_alt _                                 = False 
+
+ppr_alt_con con pp_con
+  = if isSymLexeme con then ppParens pp_con else pp_con
 \end{code}
 
 \begin{code}
@@ -314,14 +345,11 @@ ppr_alts pe (AlgAlts alts deflt)
                    ppCat [ppParens (ppInterleave ppComma (map (pMinBndr pe) params)),
                           ppStr "->"]
                else
-                   ppCat [ppr_con con (pCon pe con),
+                   ppCat [ppr_alt_con con (pCon pe con),
                           ppInterleave ppSP (map (pMinBndr pe) params),
                           ppStr "->"]
               )
             4 (ppr_expr pe expr)
-      where
-       ppr_con con pp_con
-         = if isSymLexeme con then ppParens pp_con else pp_con
 
 ppr_alts pe (PrimAlts alts deflt)
   = ppAboves [ ppAboves (map ppr_alt alts), ppr_default pe deflt ]
@@ -359,7 +387,7 @@ pprBigCoreBinder sty binder
 
     pragmas =
        ifnotPprForUser sty
-        (ppIdInfo sty binder True{-specs, please-} id nullIdEnv
+        (ppIdInfo sty binder False{-no specs, thanks-} id nullIdEnv
          (getIdInfo binder))
 
 pprBabyCoreBinder sty binder