Simon's big boxy-type commit

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

diff --git a/ghc/compiler/hsSyn/HsExpr.lhs b/ghc/compiler/hsSyn/HsExpr.lhs
index 86c4190..dbdd24c 100644 (file)
--- a/ghc/compiler/hsSyn/HsExpr.lhs
+++ b/ghc/compiler/hsSyn/HsExpr.lhs
@@ -14,13 +14,13 @@ import HsPat                ( LPat )
 import HsLit           ( HsLit(..), HsOverLit )
 import HsTypes         ( LHsType, PostTcType )
 import HsImpExp                ( isOperator, pprHsVar )
-import HsBinds         ( HsLocalBinds, DictBinds, isEmptyLocalBinds )
+import HsBinds         ( HsLocalBinds, DictBinds, ExprCoFn, isEmptyLocalBinds )
 
 -- others:
 import Type            ( Type, pprParendType )
 import Var             ( TyVar, Id )
 import Name            ( Name )
-import BasicTypes      ( IPName, Boxity, tupleParens, Fixity(..) )
+import BasicTypes      ( IPName, Boxity, tupleParens, Arity, Fixity(..) )
 import SrcLoc          ( Located(..), unLoc )
 import Outputable      
 import FastString
@@ -254,6 +254,9 @@ Everything from here on appears only in typechecker output.
                (LHsExpr id)
                [id]
 
+  |  HsCoerce  ExprCoFn        -- TRANSLATION
+               (HsExpr id)
+
 type PendingSplice = (Name, LHsExpr Id)        -- Typechecked splices, waiting to be 
                                        -- pasted back in by the desugarer
 \end{code}
@@ -415,6 +418,8 @@ ppr_expr (DictApp expr dnames)
   = hang (ppr_lexpr expr)
         4 (brackets (interpp'SP dnames))
 
+ppr_expr (HsCoerce co_fn e) = ppr_expr e
+
 ppr_expr (HsType id) = ppr id
 
 ppr_expr (HsSpliceE s)       = pprSplice s
@@ -613,6 +618,14 @@ data Match id
                                --      Nothing after typechecking
        (GRHSs id)
 
+matchGroupArity :: MatchGroup id -> Arity
+matchGroupArity (MatchGroup (match:matches) _)
+  = ASSERT( all ((== n_pats) . length . hsLMatchPats) matches )
+       -- Assertion just checks that all the matches have the same number of pats
+    n_pats
+  where
+    n_pats = length (hsLMatchPats match)
+
 hsLMatchPats :: LMatch id -> [LPat id]
 hsLMatchPats (L _ (Match pats _ _)) = pats