small update so that retyping works

[cc1516.git] / sem.icl

diff --git a/sem.icl b/sem.icl
index 7af3b20..e2227d1 100644 (file)
--- a/sem.icl
+++ b/sem.icl
@@ -18,6 +18,7 @@ import StdString
 import StdTuple
 import StdList
 import StdBool
+import GenEq
 
 from Text import class Text(concat), instance Text String
 
@@ -32,7 +33,7 @@ from parse import :: ParserOutput, :: Error
 instance MonadTrans (StateT Gamma) where
     liftT m = StateT \s-> m >>= \a-> return (a, s)
 
-get = gets id
+get :== gets id
 
 sem :: AST -> SemOutput
 sem (AST vd fd) = case runStateT m ('Map'.newMap, getRandomStream 1) of
@@ -40,27 +41,59 @@ sem (AST vd fd) = case runStateT m ('Map'.newMap, getRandomStream 1) of
     Right ((vds, fds), gamma) = Right ((AST vds fds), gamma)
 where 
     m :: Env ([VarDecl], [FunDecl])
-    m = mapM semVarDecl vd >>= \vds ->
-        mapM semFunDecl fd >>= \fds -> 
-        pure (vds, fds)
+    m = mapM semVarDecl vd >>= \vd1 ->
+        mapM semFunDecl fd >>= \fd1 -> 
+       mapM semVarDecl vd1 >>= \vd2 ->
+        mapM semFunDecl fd1 >>= \fd2 -> 
+       mapM semVarDecl vd2 >>= \vd3 ->
+        mapM semFunDecl fd2 >>= \fd3 -> 
+       mapM semVarDecl vd3 >>= \vd4 ->
+        mapM semFunDecl fd3 >>= \fd4 ->  //Dit is puur om te proberen
+        pure (vd4, fd4)
 
 semFunDecl :: FunDecl -> Env FunDecl
 semFunDecl fd=:(FunDecl p f args mt vds stmts) = 
-    saveGamma >>= \gamma ->
     (case mt of
-        Nothing = let t = IdType f in putIdent f t >>| pure t
+        Nothing = genType args >>= \infft->putIdent f infft >>| pure infft
         Just t = putIdent f t >>| pure t) >>= \ft ->
-       matchFunctions args ft >>|
+    saveGamma >>= \gamma ->
+       matchFunctions args ft >>= \tres->
     mapM semVarDecl vds >>= \newvds->
-    mapM_ (checkStmt $ resultType ft) stmts >>| 
-    restoreGamma gamma >>| 
-       pure (FunDecl p f args mt newvds stmts) 
-
-matchFunctions :: [String] Type -> Env Void
-matchFunctions [] (_ ->> _) = liftT $ Left $ Error "Niet genoeg argumentenerror"
-matchFunctions [] t = pure Void
+    mapM (checkStmt tres) stmts >>= \newstmts->
+       case mt of
+               Nothing = inferReturnType stmts
+                       >>= \returntype->reconstructType args tres 
+                       >>= \ftype->restoreGamma gamma 
+                       >>| putIdent f ftype >>| pure (
+                       FunDecl p f args (Just ftype) newvds newstmts)
+               Just t = restoreGamma gamma 
+                       >>| pure (FunDecl p f args mt newvds newstmts) 
+
+inferReturnType :: [Stmt] -> Env Type
+inferReturnType [] = pure VoidType
+inferReturnType [ReturnStmt (Just t):rest] = typeExpr t
+inferReturnType [ReturnStmt _:rest] = pure VoidType
+inferReturnType [_:rest] = inferReturnType rest
+
+reconstructType :: [String] Type -> Env Type
+reconstructType [] t = pure t
+reconstructType [x:xs] t = gets (\(st, r)->'Map'.get x st)
+       >>= \mtype->case mtype of
+               Nothing = liftT $ Left $ Error "Not used ????"
+               Just type = reconstructType xs t >>= \resttype->pure (type ->> resttype)
+
+genType :: [String] -> Env Type
+genType [] = freshIdent >>= \fi->pure $ IdType fi
+genType [x:xs] = liftM2 (->>) (freshIdent >>= \fi->pure $ IdType fi)
+       (genType xs)
+
+matchFunctions :: [String] Type -> Env Type
+matchFunctions [] (_ ->> _) = liftT $ Left $ Error "Not enough arguments"
+matchFunctions _ (VoidType ->> _) = liftT $ Left $ Error "Cannot have a void type in the middle of the function definition"
 matchFunctions [x:xs] (t1 ->> t2) = 
        modify (\(st, r)->('Map'.put x t1 st, r)) >>| matchFunctions xs t2
+matchFunctions [] t = pure t
+matchFunctions _ t = liftT $ Left $ Error "Too much argumnts"
 
 semVarDecl :: VarDecl -> Env VarDecl
 semVarDecl (VarDecl pos type ident ex) = unify type ex
@@ -105,10 +138,9 @@ typeExpr (VarExpr p (VarDef ident fs)) = gets (\(st, r)->'Map'.get ident st)
     >>= \mt->case mt of
         Nothing = liftT $ Left $ UndeclaredVariableError p ident
         Just t = unify t fs
-
 typeOp2 :: Expr Expr Op2 [Type] Type -> Env Type
 typeOp2 e1 e2 op ts ret = typeExpr e1 >>= \t1-> typeExpr e2 >>= \t2->
-    unify t1 t2 >>= \t3->if (isMember t3 ts) (pure ret)
+    unify t1 t2 >>= \t3->if (isMember t3 [IdType "":ts]) (pure ret)
         (liftT $ Left $ OperatorError (extrPos e1) op t3)
 
 buildFunctionType :: String [Expr] -> Env Type 
@@ -145,10 +177,12 @@ instance unify Expr where
                        "Expression cannot be a higher order function. Yet..."
        unify VoidType e = liftT $ Left $ ParseError (extrPos e)
                        "Expression cannot be a Void type."
-       unify (IdType _) e = liftT $ Left $ ParseError (extrPos e)
-                       "Expression cannot be an polymorf type."
+//     unify (IdType _) e = liftT $ Left $ ParseError (extrPos e)
+//                     "Expression cannot be an polymorf type."
     unify VarType e = typeExpr e
     //we have to cheat to decorate the error, can be done nicer?
+       unify t=:(IdType id) e = typeExpr e >>= \tex->unify t tex
+               >>= \type->putIdent id type >>| pure type
     unify t e = StateT $ \s0 -> let res = runStateT m s0 in case res of
         Left err = Left $ decErr e err
         Right t = Right t //note, t :: (Type, Gamma) 
@@ -164,6 +198,7 @@ instance unify Type where
     unify (ListType t1) (ListType t2) = unify t1 t2 >>| (pure $ ListType t1)
     unify (ta1 ->> ta2) (tb1 ->> tb2) = unify ta1 tb1 >>= \ta-> unify ta2 tb2 
         >>= \tb-> pure (ta ->> tb)
+    unify VoidType VoidType = pure VoidType
        unify t1 t2 = liftT $ Left $ UnifyError zero t1 t2
 
 instance zero Pos where
@@ -249,4 +284,9 @@ saveGamma :: Env Gamma
 saveGamma = get
 
 restoreGamma :: Gamma -> Env Void
-restoreGamma g = put g
+restoreGamma (oldstate, _) = gets snd >>= \newr->put (oldstate, newr)
+
+derive gEq Type
+instance == Type where 
+       (==) (IdType _) (IdType _) = True
+       (==) o1 o2 = gEq{|*|} o1 o2