From a5d1526fbbec4b89c0e400c4e501668fa14cc51c Mon Sep 17 00:00:00 2001
From: John Maddock <john@johnmaddock.co.uk>
Date: Fri, 8 Feb 2002 12:43:59 +0000
Subject: [PATCH] Added docs for forward lookahead asserts.

[SVN r12757]
---
 syntax.htm | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/syntax.htm b/syntax.htm
index 10e01b8d..f6b18f8f 100644
--- a/syntax.htm
+++ b/syntax.htm
@@ -157,9 +157,18 @@ but don't want the parenthesis to spit out another marked sub-expression,
 in this case a non-marking parenthesis (?:expression) can be used.
 For example the following expression creates no sub-expressions: </p>
 
-<p>&quot;(?:abc)*&quot; <br>
-&nbsp; <br>
-&nbsp; </p>
+<p>&quot;(?:abc)*&quot;</p>
+
+<p><em>Forward Lookahead Asserts</em>&nbsp; </p>
+
+<p>There are two forms of these; one for positive forward
+lookahead asserts, and one for negative lookahead asserts:</p>
+
+<p>&quot;(?=abc)&quot; matches zero characters only if they are
+followed by the expression &quot;abc&quot;.</p>
+
+<p>&quot;(?!abc)&quot; matches zero characters only if they are
+not followed by the expression &quot;abc&quot;.</p>
 
 <p><i>Alternatives</i> </p>