From 6afb62f51040bb5492397b1e3dbc046d4fe19320 Mon Sep 17 00:00:00 2001
From: Casey Klein <clklein@racket-lang.org>
Date: Wed, 28 Jan 2009 16:30:22 +0000
Subject: [PATCH] Fixed a bug in find-base-cases.

svn: r13303
---
 collects/redex/private/rg-test.ss | 7 +++++++
 collects/redex/private/rg.ss      | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/collects/redex/private/rg-test.ss b/collects/redex/private/rg-test.ss
index 560e7d7ef8..761f2a5ec0 100644
--- a/collects/redex/private/rg-test.ss
+++ b/collects/redex/private/rg-test.ss
@@ -48,6 +48,13 @@
           (v . (2 0)) (v-e . (2 2 2 2 1)) (v-v . (0 2))
           (x . (0)) (x-e . (2 2 2 2 1 3)) (x-v . (2 2)) (x-x . (0)))))
 
+(let ()
+  (define-language L
+    (x (variable-prefix x)
+       (variable-except y))
+    (y y))
+  (test (hash-ref (find-base-cases L) 'x) '(0 0)))
+
 (let ()
   (define-language lang
     (e number x y)
diff --git a/collects/redex/private/rg.ss b/collects/redex/private/rg.ss
index d86ffa5ef4..56fe698ed9 100644
--- a/collects/redex/private/rg.ss
+++ b/collects/redex/private/rg.ss
@@ -429,6 +429,8 @@ To do a better job of not generating programs with free variables,
              (set! nts (cons (symbol->nt pat) nts)))]
           [`(cross ,(? symbol? x-nt))
            (set! nts (cons x-nt nts))]
+          [`(variable-except ,s ...) (void)]
+          [`(variable-prefix ,p) (void)]
           [`() (void)]
           [(struct ellipsis (_ p _ _))
            (loop p)]