| Subject: | Spurious warnings on grammar re-parsing |
After version 1.94 P::RD emits warnings if one parses a specific grammar
more than once. As long as the grammar contains:
sentence: ( token1 | token2 | ... | tokenN ) (s)
rebuilding of such a grammar with P::RD->new ($gr) will trigger a
multitude of:
Use of uninitialized value in subtraction (-) at lib/Parse/RecDescent.pm
line 1885.
The alternative but semantically identical syntax does not produce any
warnings:
token: token1 | token2 | ... | tokenN
sentence: tokens(s)
Complete standalone test attached.
| Subject: | reentry.t |
use warnings;
use strict;
$^W++; # for some reason use warnings doesn't cut it
use Test::More;
use Test::Warn;
use Parse::RecDescent;
my $g1 = <<'EOG';
{
use warnings;
use strict;
my @seq;
}
genome : base(s)
{ $return = \@seq }
base : A | C | G | T
A : /a/ { push @seq, $item[0] }
C : /c/ { push @seq, $item[0] }
G : /g/ { push @seq, $item[0] }
T : /t/ { push @seq, $item[0] }
EOG
my $g2 = <<'EOG';
{
use warnings;
use strict;
my @seq;
}
genome : ( A | C | G | T )(s)
{ $return = \@seq }
A : /a/ { push @seq, $item[0] }
C : /c/ { push @seq, $item[0] }
G : /g/ { push @seq, $item[0] }
T : /t/ { push @seq, $item[0] }
EOG
my @sequences = (qw/aatgcttgc cctggattcg ctggaagtc ctgXc/);
plan tests => @sequences * 4;
for my $to_sequence (@sequences) {
my ($p1, $p2);
warnings_are (sub {
$p1 = Parse::RecDescent->new ($g1);
}, [], 'no warnings emitted during grammar1 parsing');
warnings_are (sub {
$p2 = Parse::RecDescent->new ($g2);
}, [], 'no warnings emitted during grammar2 parsing');
warnings_are (sub {
is_deeply (
$p1->genome ($to_sequence),
$p2->genome ($to_sequence),
'grammars produce same result'
);
}, [], 'no warnings emitted during grammar execution');
}