From 5fd3de16f4a6de8d5c28c7a80e9a4965eede2ab3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dag-Erling=20Sm=C3=B8rgrav?= <des@des.dev>
Date: Fri, 26 Apr 2024 12:25:46 +0200
Subject: [PATCH] Allow the minimum count of a bound to be omitted.

---
 doc/tre-syntax.html | 15 +++++++++++----
 lib/tre-parse.c     |  2 ++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/doc/tre-syntax.html b/doc/tre-syntax.html
index 13ccb54..640bb17 100644
--- a/doc/tre-syntax.html
+++ b/doc/tre-syntax.html
@@ -126,16 +126,23 @@ <h3>Repeat operators</h3>
 
 <ol>
 <li><tt>{</tt><i>m</i><tt>,</tt><i>n</i><tt>}</tt></li>
+<li><tt>{,</tt><i>n</i><tt>}</tt></li>
 <li><tt>{</tt><i>m</i><tt>,}</tt></li>
 <li><tt>{</tt><i>m</i><tt>}</tt></li>
+<li><tt>{,}</tt></li>
 </ol>
 
 <p>
 An atom followed by [1] matches a sequence of <i>m</i> through <i>n</i>
-(inclusive) matches of the atom.  An atom followed by [2]
-matches a sequence of <i>m</i> or more matches of the atom.  An atom
-followed by [3] matches a sequence of exactly <i>m</i> matches of the
-atom.
+(inclusive) matches of the atom.
+An atom followed by [2] matches a sequence of up to <i>n</i> matches
+of the atom.
+An atom followed by [3] matches a sequence of <i>m</i> or more matches
+of the atom.
+An atom followed by [4] matches a sequence of exactly <i>m</i> matches
+of the atom.
+An atom followed by [5] matches a sequence of zero or more matches of
+the atom.
 </p>
 
 
diff --git a/lib/tre-parse.c b/lib/tre-parse.c
index 82004cf..b1d146c 100644
--- a/lib/tre-parse.c
+++ b/lib/tre-parse.c
@@ -622,6 +622,8 @@ tre_parse_bound(tre_parse_ctx_t *ctx, tre_ast_node_t **result)
   max = min;
   if (r < ctx->re_end && *r == CHAR_COMMA)
     {
+      if (min < 0)
+	min = 0;
       r++;
       DPRINT(("tre_parse:   max count: '%.*" STRF "'\n", REST(r)));
       max = tre_parse_int(&r, ctx->re_end);