infer for FunExpr

diff --git a/sem.icl b/sem.icl
index 1e9846d..fa4b3ae 100644 (file)
--- a/sem.icl
+++ b/sem.icl
@@ -231,8 +231,13 @@ instance infer Expr where
         pure (compose s1 s2, TupleType (t1,t2))
 
     FunExpr _ f args fs = //todo: fieldselectors
-        lookup f >>= \expected ->
-        mapM infer args >>= \argTypes
+        lookup f >>= instantiate >>= \expected ->
+        let accTypSub = (\(s,ts) e->infer e >>= \(s_,et)->pure (compose s_ s,ts++[et])) in
+        foldM accTypSub (zero,[]) args >>= \(s1, argTs)->
+        fresh >>= \tv->
+        let given = foldr (->>) tv argTs in
+        lift (unify expected given) >>= \s2->
+        pure (compose s1 s2, subst s2 tv)
 
     IntExpr _ _ = pure $ (zero, IntType)
     BoolExpr _ _ = pure $ (zero, BoolType)