Merge pull request #5 from andmkent/master

fixed mutation let-aliasing bug
2015-01-05 09:15:57 -05:00 · 2015-01-05 09:15:57 -05:00 · dc2ce38aef
commit dc2ce38aef
parent 8a663a5499 9d41048747
2 changed files with 11 additions and 1 deletions
--- a/typed-racket-lib/typed-racket/typecheck/tc-let-unit.rkt
+++ b/typed-racket-lib/typed-racket/typecheck/tc-let-unit.rkt
@ -52,7 +52,7 @@
        (match e-r
          [(list (tc-result: e-ts (FilterSet: fs+ fs-) os) ...)
           (values e-ts
-                   os
+                   (map (λ (o n) (if (is-var-mutated? n) -empty-obj o)) os names)
                   (apply append
                          (for/list ([n (in-list names)]
                                     [t (in-list e-ts)]
--- a/typed-racket-test/unit-tests/typecheck-tests.rkt
+++ b/typed-racket-test/unit-tests/typecheck-tests.rkt
@ -3392,6 +3392,16 @@
               (void))
             -Void]
       
+       [tc-err (let ()
+                 (: foo (-> Any Number))
+                 (define foo
+                   (λ (x) (let ([x* x])
+                            (begin
+                              (set! x* "sneaky string")
+                              (if (number? x)
+                                  x*
+                                  42))))))]
+       
       ;; tests looking up path-types into unions
       [tc-e (let ()
               (: foo ((U (Pairof Number Number) (Pairof Number String)) -> Number))