libparse-recdescent-perl/demo/demo_implicit.pl

32 lines
575 B
Perl
Executable File

#! /usr/local/bin/perl -sw
# IMPLICIT SUB RULES, OKAY!
use strict;
use Parse::RecDescent;
my $grammar =
q{
{ my $state = "happy"; }
testimony : declaration(s)
{ print "Ended up $state\n"; }
declaration : 'I' ('like'|'loathe')(s) ('ice-cream'|'lawyers')
{ print "$item[3]\n";
$state = 'happy/sad'; }
| 'I' ("can't"|"can") ('fly'|'swim')
{ print "$item[3]\n";
$state = 'able/unable'; }
| <error>
};
my $parse = new Parse::RecDescent ($grammar);
my $input;
while (defined ($input = <>))
{
$parse->testimony($input) or print "huh?\n";
}