From 54fb498c63f58283135ac0504236ec7afcb54861 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Fri, 15 Jun 2018 15:01:51 -0700
Subject: [PATCH] curly tests

---
 brag/examples/curly-quantifier.rkt  | 5 +++--
 brag/test/test-curly-quantifier.rkt | 5 +++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/brag/examples/curly-quantifier.rkt b/brag/examples/curly-quantifier.rkt
index 7f0d961..a2de3ac 100644
--- a/brag/examples/curly-quantifier.rkt
+++ b/brag/examples/curly-quantifier.rkt
@@ -1,7 +1,8 @@
 #lang brag
 ;; test the curly quantifier
-start : a-rule | b-rule | c-rule | d-rule
+start : a-rule | b-rule | c-rule | d-rule | e-rule
 a-rule : "a"{2} ; exactly 2
 b-rule : "b"{,2} ; up to 2
 c-rule : "c"{2,} ; 2 or more
-d-rule : "d"{2,3} ; 2 or 3
\ No newline at end of file
+d-rule : "d"{2,3} ; 2 or 3
+e-rule : "e"{} ; 0 or more
\ No newline at end of file
diff --git a/brag/test/test-curly-quantifier.rkt b/brag/test/test-curly-quantifier.rkt
index c531368..ad27540 100755
--- a/brag/test/test-curly-quantifier.rkt
+++ b/brag/test/test-curly-quantifier.rkt
@@ -21,3 +21,8 @@
 (check-equal? (parse-to-datum "dd") '(start (d-rule "d" "d")))
 (check-equal? (parse-to-datum "ddd") '(start (d-rule "d" "d" "d")))
 (check-exn exn:fail:parsing? (λ () (parse-to-datum "dddd")))
+
+(check-equal? (syntax->datum ((make-rule-parser e-rule) "")) '(e-rule)) ; to prevent ambiguity with b-rule while parsing empty string
+(check-equal? (parse-to-datum "e") '(start (e-rule "e")))
+(check-equal? (parse-to-datum "ee") '(start (e-rule "e" "e")))
+(check-equal? (parse-to-datum "eee") '(start (e-rule "e" "e" "e")))
\ No newline at end of file