pure (compose s3 $ compose s2 s1, subst s3 wht)
AssStmt (VarDef k fs) e =
- infer e >>= \(s1, et)->
- applySubst s1 >>|
- changeGamma (extend k (Forall [] et)) >>| //todo: fieldselectors
- pure (s1, VoidType)
+ lookup k >>= \expected ->
+ infer e >>= \(s1, given)->
+ lift (unify expected given) >>= \s2->
+ let s = compose s2 s1 in
+ applySubst s >>|
+ changeGamma (extend k (Forall [] given)) >>| //todo: fieldselectors
+ pure (s, VoidType)
FunStmt f es = undef //what is this?
applySubst (compose s2 s1) >>|
pure (compose s2 s1, [v_:vs_])
-// mapM processGamma dcls//
-
-////add the infered type in Gamma to AST constructs
-//class processGamma a :: a -> Typing a//
-
-//instance processGamma VarDecl where
-// processGamma v=:(VarDecl p _ k e) =
-// gamma >>= \g -> case 'Map'.member k g of
-// False = undef
-// True = instantiate ('Map'.find k g) >>= \t->
-// pure (VarDecl p (Just t) k e)//
-
-//instance processGamma FunDecl where
-// processGamma v=:(FunDecl p k args _ vds stmts) =
-// gamma >>= \g -> case 'Map'.member k g of
-// False = undef
-// True = instantiate ('Map'.find k g) >>= \t->
-// pure (FunDecl p k args (Just t) vds stmts)
-
introduce :: String -> Typing Type
introduce k =
fresh >>= \tv ->