typing

[minfp.git] / check.icl

diff --git a/check.icl b/check.icl
index abff97a..2cc76ac 100644 (file)
--- a/check.icl
+++ b/check.icl
@@ -129,9 +129,21 @@ infer env (Lambda x b)
 //     =              infer env e1
 //     >>= \(s1, t1)->infer ('Data.Map'.put x (generalize (apply s1 env) t1) env) e2
 //     >>= \(s2, t2)->pure (s1 oo s2, t2)
-infer env (Let [(x, e1)] e2)
-       =              fresh
-       >>= \tv->      let env` = 'Data.Map'.put x (Forall [] tv) env
-                      in infer env` e1
-       >>= \(s1,t1)-> infer ('Data.Map'.put x (generalize (apply s1 env`) t1) env`) e2
-       >>= \(s2, t2)->pure (s1 oo s2, t2)
+//infer env (Let [(x, e1)] e2)
+//     =              fresh
+//     >>= \tv->      let env` = 'Data.Map'.put x (Forall [] tv) env
+//                    in infer env` e1
+//     >>= \(s1,t1)-> unify t1 tv
+//     >>= \t->infer ('Data.Map'.put x (generalize (apply s1 env`) t1) env`) e2
+//     >>= \(s2, t2)->pure (s1 oo s2, t2)
+infer env (Let xs e2)
+       # (ns, bs) = unzip xs
+       =              sequence [fresh\\_<-ns]
+       >>= \tvs->     let env` = foldr (uncurry putenv) env (zip2 ns tvs)
+                      in unzip <$> sequence (map infer env`) bs
+       >>= \(ss,ts)-> unify t1 tv
+//     >>= \t->infer ('Data.Map'.put x (generalize (apply s1 env`) t1) env`) e2
+//     >>= \(s2, t2)->pure (s1 oo s2, t2)
+where
+       putenv :: [Char] -> (Type TypeEnv -> TypeEnv)
+       putenv k = 'Data.Map'.put k o Forall []