Fix typechecking with bindings

[scheme.git] / typecheck.scm

diff --git a/typecheck.scm b/typecheck.scm
index b3466751fdf7f4161963d3904c13f970b8798a76..f6d7c86465f4869043b3d2fcb9560e42603258d7 100644 (file)
--- a/typecheck.scm
+++ b/typecheck.scm
@@ -194,10 +194,14 @@
     
     (define (get-bindings product-types pattern)
       (define (go product-type product)
-            (case (ast-type x)
+       (case (ast-type product)
          ['var (list (cons product product-type))]
                                        ; an inner pattern match
-              ['app (get-bindings product-type product)]))
+         ['app (let* ([inner-sum (car product)]
+                      [inner-sums (cdr (assoc product-type dls))]
+                      [inner-product-types (cdr (assoc inner-sum inner-sums))])
+                 (get-bindings inner-product-types product))]
+         [else '()]))
       (flat-map go product-types (cdr pattern)))
 
     
@@ -211,6 +215,7 @@
            (let* ([names (cdr pattern)]
                   [product-types (cdr sum)]
                   [new-env (append (get-bindings product-types pattern) env)])
+
              (check dls new-env expr)))]
                                        ; pattern match with binding and no constructor
        ['var (check dls (env-insert env pattern switch-type) expr)]