X-Git-Url: https://git.hcoop.net/hcoop/domtool2.git/blobdiff_plain/fd53df8fe8e39d722b7562c4e9d68ab4d7937577..75d4c2d6fb7996625d062f5949ceb2e66c0a70ab:/src/tycheck.sml

diff --git a/src/tycheck.sml b/src/tycheck.sml
index def1463..f68100f 100644
--- a/src/tycheck.sml
+++ b/src/tycheck.sml
@@ -571,6 +571,33 @@ fun checkExp G (eAll as (e, loc)) =
 
 	  | ESkip => (TAction ((CPrefix (CRoot, loc), loc),
 			       SM.empty, SM.empty), loc)
+
+	  | EIf (e1, e2, e3) =>
+	    let
+		val t = (newUnif (), loc)
+
+		val t1 = checkExp G e1
+		val t2 = checkExp G e2
+		val t3 = checkExp G e3
+		val bool = (TBase "bool", loc)
+	    in
+		(subTyp (t1, bool))
+		handle Unify ue =>
+		       dte (WrongType ("\"If\" test",
+				       e1,
+				       t1,
+				       bool,
+				       SOME ue));
+		subTyp (t2, t);
+		(subTyp (t3, t))
+		handle Unify ue =>
+		       dte (WrongType ("\"Else\" case",
+				       eAll,
+				       t3,
+				       t2,
+				       SOME ue));
+		t
+	    end
     end
 
 exception Ununif