Author: lwall
Date: 2009-09-02 19:09:15 +0200 (Wed, 02 Sep 2009)
New Revision: 28169
Modified:
docs/Perl6/Spec/S05-regex.pod
Log:
[S05] document how :my works in regexen
Modified: docs/Perl6/Spec/S05-regex.pod
===================================================================
--- docs/Perl6/Spec/S05-regex.pod 2009-09-02 16:35:17 UTC (rev 28168)
+++ docs/Perl6/Spec/S05-regex.pod 2009-09-02 17:09:15 UTC (rev 28169)
@@ -16,8 +16,8 @@
Created: 24 Jun 2002
- Last Modified: 11 Aug 2009
- Version: 101
+ Last Modified: 2 Sep 2009
+ Version: 102
This document summarizes Apocalypse 5, which is about the new regex
syntax. We now try to call them I<regex> rather than "regular
@@ -554,6 +554,29 @@
m:fuzzy(fuzzyargs); pattern ;
+=item *
+
+Any grammar regex is really just a kind of method, and you may
+declare variables in such a routine using a colon followed by any
+scope declarator parsed by the Perl6 grammar, including C<my>,
+C<our>, C<state>, and C<constant>. A single statement (up through
+a terminating semicolon) is parsed as normal Perl 6 code:
+
+ token prove-nondeterministic-parsing {
+ :my $threshold = rand;
+ 'maybe' \s+ <it($threshold)>
+ }
+
+Such declarations do not terminate longest-token-matching,
+so an otherwise useless declaration may be used as a peg
+to hang side effects on without changing how the subsequent
+pattern matches:
+
+ rule breaker {
+ :state $ = say "got here at least once";
+ ...
+ }
+
=back
=head1 Changed metacharacters
