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#!/usr/bin/perl
# Copyright 2022 Jeffrey Kegler
# This file is part of Marpa::R2. Marpa::R2 is free software: you can
# redistribute it and/or modify it under the terms of the GNU Lesser
# General Public License as published by the Free Software Foundation,
# either version 3 of the License, or (at your option) any later version.
#
# Marpa::R2 is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser
# General Public License along with Marpa::R2. If not, see
# http://www.gnu.org/licenses/.
# Rewriting tests, to check the accuracy of the
# tracing documentation.
use 5.010001;
use strict;
use warnings;
use Fatal qw(open close);
use Test::More tests => 2;
use lib 'inc';
use Marpa::R2::Test;
use Marpa::R2;
my $chaf_rule = {
lhs => 'statement',
rhs => [
qw/optional_whitespace expression
optional_whitespace optional_modifier
optional_whitespace/
]
};
my $separated_sequence_rule = {
lhs => 'statements',
rhs => [qw/statement/],
separator => 'comma',
min => 1
};
our $null_parse = 'Null parse';
my $sequence_rule = {
lhs => 'block',
rhs => [qw/statements/],
min => 0,
action => 'main::null_parse'
};
my $grammar = Marpa::R2::Grammar->new(
{ start => 'block',
terminals => [qw(block whitespace modifier expression comma)],
rules => [
$chaf_rule,
$separated_sequence_rule,
$sequence_rule,
{ lhs => 'optional_whitespace', rhs => [qw(whitespace)] },
{ lhs => 'optional_whitespace', },
{ lhs => 'optional_modifier', rhs => [qw(modifier)] },
{ lhs => 'optional_modifier', },
],
}
);
$grammar->precompute();
my $recce = Marpa::R2::Recognizer->new( { grammar => $grammar } );
# While we are at it, test the handling of null parses in
# the Single Parse Evaluator
$recce->end_input();
# Marpa::R2::Display::End
my $show_rules_output = $grammar->show_rules();
Marpa::R2::Test::is( $show_rules_output, <<'END_RULES', 'Rewritten Rules' );
0: statement -> optional_whitespace expression optional_whitespace optional_modifier optional_whitespace
1: statements -> statement+ /* discard_sep */
2: block -> statements*
3: optional_whitespace -> whitespace
4: optional_whitespace -> /* empty !used */
5: optional_modifier -> modifier
6: optional_modifier -> /* empty !used */
END_RULES
my $value_ref = $recce->value();
my $value = $value_ref ? ${$value_ref} : 'No Parse';
Marpa::R2::Test::is( $value, 'Null parse', 'Null parse value' );
1; # In case used as "do" file
# Local Variables:
# mode: cperl
# cperl-indent-level: 4
# fill-column: 100
# End:
# vim: expandtab shiftwidth=4:
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