Working on algorithm M

diff --git a/sem.icl b/sem.icl
index 8cc3df9..1e9846d 100644 (file)
--- a/sem.icl
+++ b/sem.icl
@@ -204,6 +204,7 @@ instance infer Expr where
  infer e = case e of
     VarExpr _ (VarDef k fs) = (\t->(zero,t)) <$> (lookup k >>= instantiate)
     //instantiate is key for the let polymorphism!
+    //TODO: field selectors
 
     Op2Expr _ e1 op e2 =
         infer e1 >>= \(s1, t1) -> 
@@ -220,9 +221,18 @@ instance infer Expr where
         let given = t1 ->> tv in 
         op1Type op >>= \expected ->
         lift (unify expected given) >>= \s2 ->
-        pure ((compose s1 s2), subst s2 tv)
+        pure (compose s1 s2, subst s2 tv)
 
+    EmptyListExpr _ = (\tv->(zero,tv)) <$> fresh
 
+    TupleExpr _ (e1, e2) = 
+        infer e1 >>= \(s1, t1) -> 
+        infer e2 >>= \(s2, t2) ->
+        pure (compose s1 s2, TupleType (t1,t2))
+
+    FunExpr _ f args fs = //todo: fieldselectors
+        lookup f >>= \expected ->
+        mapM infer args >>= \argTypes
 
     IntExpr _ _ = pure $ (zero, IntType)
     BoolExpr _ _ = pure $ (zero, BoolType)