Execution → Preprocessing

[darcs-mirror-sem_syn.git] / Type.hs

diff --git a/Type.hs b/Type.hs
index 35e615e..af2e298 100644 (file)
--- a/Type.hs
+++ b/Type.hs
@@ -13,6 +13,26 @@ import Data.List (nub,nubBy,union)
 import Data.Map (Map)
 import qualified Data.Map as Map
 
+-- type erasure
+eraseType (AST decls) =
+    AST $ map (\(Decl f ftype ps e) ->
+             Decl f FTUndet (map eraseTypeP ps) (eraseTypeE e)) decls 
+
+eraseTypeP (PVar id t varname)   
+    = PVar id TUndet varname
+eraseTypeP (PCon id t conname ps)
+    = PCon id TUndet conname (map eraseTypeP ps)
+
+eraseTypeE (EVar id t varname) 
+    = EVar id TUndet varname 
+eraseTypeE (ECon id t conname es)
+    = ECon id TUndet conname (map eraseTypeE es)
+eraseTypeE (EFun id t funname es)
+    = EFun id TUndet funname (map eraseTypeE es)
+
+eraseTypeT (TAST decls) = 
+    TAST $ map (\(TDecl f ps es bs) -> 
+                    TDecl f (map eraseTypeP ps) (map eraseTypeE es)bs) decls
 
 -- type inference
 
@@ -204,7 +224,9 @@ assignTypeVars tmpMap typeMap (Decl fname ftype ps e) =
                      do { es' <- mapM assignTypeVarsE es 
                         ; unifyFT t' (TFun [] (map typeofE es') (TVar i))
                         ; unifyT  t  (TVar i)
-                        ; return $ ECon id (TVar i) c es' }}
+                        ; return $ ECon id (TVar i) c es' }
+                 Nothing -> fail $ "No type " ++ show c ++ " in type map"
+             }
       assignTypeVarsE (EFun id t f es) =
           do { i <- newTypeVar
              ; case lookup f (typeMap ++ tmpMap)  of
@@ -243,4 +265,4 @@ assignTypeVars tmpMap typeMap (Decl fname ftype ps e) =
           TCon t (map (replaceTVar table) ts)
 
                      
-                          
\ No newline at end of file
+