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original commit: 9f659c7df30b42ec49e6da1d85b5a0e5605fdcd1
2013-05-21 07:53:43 +01:00 · 2013-05-21 07:53:43 +01:00 · 77762e7742
commit 77762e7742
parent 0ab3099f7e
1 changed files with 2 additions and 1 deletions
--- a/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/infer/constraints.rkt
+++ b/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/infer/constraints.rkt
@ -12,7 +12,8 @@
 (import restrict^ dmap^)
 (export constraints^)

-
+;; It's hard to remove this use of exceptions
+;; because there's no monadic version of `hash-union` etc
 (define-values (fail-sym exn:infer?)
  (let ([sym (gensym 'infer-fail)])
    (values sym (λ (s) (and (pair? s) (eq? (car s) sym))))))