From 7a414869de3fad9315930ddcc6706632add45436 Mon Sep 17 00:00:00 2001
From: Chris Double <chris.double@double.co.nz>
Date: Wed, 28 Nov 2007 11:33:21 +1300
Subject: [PATCH] Support for repeat0 in ebnf

---
 extra/peg/ebnf/ebnf.factor | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/extra/peg/ebnf/ebnf.factor b/extra/peg/ebnf/ebnf.factor
index a402a0fd73..2f71ff961b 100644
--- a/extra/peg/ebnf/ebnf.factor
+++ b/extra/peg/ebnf/ebnf.factor
@@ -7,6 +7,7 @@ TUPLE: ebnf-non-terminal symbol ;
 TUPLE: ebnf-terminal symbol ;
 TUPLE: ebnf-choice options ;
 TUPLE: ebnf-sequence elements ;
+TUPLE: ebnf-repeat0 group ;
 TUPLE: ebnf-rule symbol elements ;
 TUPLE: ebnf rules ;
 
@@ -14,6 +15,7 @@ C: <ebnf-non-terminal> ebnf-non-terminal
 C: <ebnf-terminal> ebnf-terminal
 C: <ebnf-choice> ebnf-choice
 C: <ebnf-sequence> ebnf-sequence
+C: <ebnf-repeat0> ebnf-repeat0
 C: <ebnf-rule> ebnf-rule
 C: <ebnf> ebnf
 
@@ -49,6 +51,11 @@ M: ebnf-sequence ebnf-compile ( ast -- quot )
     [ call ] , \ map , \ seq , 
   ] [ ] make ;
 
+M: ebnf-repeat0 ebnf-compile ( ast -- quot )
+  [
+    ebnf-repeat0-group ebnf-compile % \ repeat0 , 
+  ] [ ] make ;
+
 M: ebnf-rule ebnf-compile ( ast -- quot )
   [
     dup ebnf-rule-symbol , \ in , \ get , \ create , 
@@ -85,7 +92,7 @@ DEFER: 'rhs'
   "{" token sp hide
   [ 'rhs' sp ] delay
   "}" token sp hide 
-  3array seq ;
+  3array seq [ first <ebnf-repeat0> ] action ;
 
 : 'rhs' ( -- parser )
   'repeat0'