matchFunctions args ft >>= \tres->
mapM semVarDecl vds >>= \newvds->
mapM (checkStmt tres) stmts >>= \newstmts->
- inferReturnType stmts >>= \returntype->
+ inferReturnType stmts >>= \returntype`->
+ unify returntype` tres >>= \returntype->
case mt of
Nothing = reconstructType args tres
+ >>= \ftype`->recoverType ftype`
>>= \ftype->restoreGamma gamma
>>| putIdent f ftype >>| pure (
FunDecl p f args (Just ftype) newvds newstmts)
Just t = restoreGamma gamma >>| updateFunType t returntype
>>= \tt-> pure (FunDecl p f args (Just tt) newvds newstmts)
+recoverType :: Type -> Env Type
+recoverType (IdType ident) = gets (\(st, r)->'Map'.get ident st)
+ >>= \mt->case mt of
+ Nothing = pure (IdType ident)
+ Just t = pure t
+recoverType (t1 ->> t2) = recoverType t1 >>= \t1`->recoverType t2
+ >>= \t2`->pure (t1` ->> t2`)
+recoverType t = pure t
+
updateFunType :: Type Type -> Env Type
+updateFunType (t1 ->> t2) t3 = updateFunType t2 t3 >>= \t2`->pure $ t1 ->> t2`
updateFunType t1 t2 = unify t1 t2
-updateFunType (t1 ->> t2) t3 = t1 ->> (updateFunType t2 t3)
inferReturnType :: [Stmt] -> Env Type
inferReturnType [] = pure VoidType
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 VoidType t = pure t
unify t VoidType = pure t
- unify VoidType VoidType = pure VoidType
unify t1 t2 = liftT $ Left $ UnifyError zero t1 t2
instance zero Pos where