#!perl
# Copyright 2012 Jeffrey Kegler
# This file is part of Marpa::XS. Marpa::XS 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::XS 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::XS. If not, see
# http://www.gnu.org/licenses/.
# The example from p. 168-169 of Leo's paper.
#
# Make sure I have a CHAF example!
#
use 5.010;
use strict;
use warnings;
use Test::More tests => 18;
use lib 'tool/lib';
use Marpa::XS::Test;
BEGIN {
Test::More::use_ok('Marpa::XS');
}
## no critic (Subroutines::RequireArgUnpacking)
sub generate_action {
my ($lhs) = @_;
return sub {
shift;
my $v_count = scalar @_;
return q{} if $v_count <= 0;
my @vals = map { $_ // q{-} } @_;
return $lhs . '(' . ( join q{;}, @vals ) . ')';
}
} ## end sub generate_action
my $C_action = generate_action('C');
my $S_action = generate_action('S');
my $default_action = generate_action(q{?});
## use critic
my $grammar = Marpa::XS::Grammar->new(
{ start => 'S',
strip => 0,
rules => [
[ 'S', [qw/a S/], 'S_action', ],
[ 'S', [qw/C/], 'S_action', ],
[ 'C', [qw(a C b)], 'C_action', ],
[ 'C', [], ],
],
terminals => [qw(a b)],
default_action => 'default_action',
}
);
$grammar->precompute();
Marpa::XS::Test::is( $grammar->show_symbols(),
<<'END_OF_STRING', 'Leo168 Symbols' );
0: a, lhs=[] rhs=[0 2 4 5 7 8] terminal
1: b, lhs=[] rhs=[2 7 8] terminal
2: S, lhs=[0 1 4 5 6] rhs=[0 4 9]
3: C, lhs=[2 3 7 8] rhs=[1 2 6 7]
4: S[], lhs=[] rhs=[5] nullable nulling
5: C[], lhs=[] rhs=[8] nullable nulling
6: S['], lhs=[9] rhs=[]
7: S['][], lhs=[10] rhs=[] nullable nulling
END_OF_STRING
Marpa::XS::Test::is( $grammar->show_rules,
<<'END_OF_STRING', 'Leo168 Rules' );
0: S -> a S /* !used */
1: S -> C /* !used */
2: C -> a C b /* !used */
3: C -> /* empty !used */
4: S -> a S
5: S -> a S[]
6: S -> C
7: C -> a C b
8: C -> a C[] b
9: S['] -> S /* vlhs real=1 */
10: S['][] -> /* empty vlhs real=1 */
END_OF_STRING
Marpa::XS::Test::is( $grammar->show_AHFA, <<'END_OF_STRING', 'Leo168 AHFA' );
* S0:
S['] -> . S
S['][] -> .
<S> => S2; leo(S['])
* S1: predict
S -> . a S
S -> . a S[]
S -> . C
C -> . a C b
C -> . a C[] b
<C> => S4; leo(S)
<a> => S1; S3
* S2: leo-c
S['] -> S .
* S3:
S -> a . S
S -> a S[] .
C -> a . C b
C -> a C[] . b
<C> => S7
<S> => S6; leo(S)
<b> => S5
* S4: leo-c
S -> C .
* S5:
C -> a C[] b .
* S6: leo-c
S -> a S .
* S7:
C -> a C . b
<b> => S8
* S8:
C -> a C b .
END_OF_STRING
my %expected = (
'a' => q{S(a;-)},
'ab' => q{S(C(a;-;b))},
'aa' => q{S(a;S(a;-))},
'aab' => q{S(a;S(C(a;-;b)))},
'aabb' => q{S(C(a;C(a;-;b);b))},
'aaa' => q{S(a;S(a;S(a;-)))},
'aaab' => q{S(a;S(a;S(C(a;-;b))))},
'aaabb' => q{S(a;S(C(a;C(a;-;b);b)))},
'aaabbb' => q{S(C(a;C(a;C(a;-;b);b);b))},
'aaaa' => q{S(a;S(a;S(a;S(a;-))))},
'aaaab' => q{S(a;S(a;S(a;S(C(a;-;b)))))},
'aaaabb' => q{S(a;S(a;S(C(a;C(a;-;b);b))))},
'aaaabbb' => q{S(a;S(C(a;C(a;C(a;-;b);b);b)))},
'aaaabbbb' => q{S(C(a;C(a;C(a;C(a;-;b);b);b);b))},
);
for my $a_length ( 1 .. 4 ) {
for my $b_length ( 0 .. $a_length ) {
my $string = ( 'a' x $a_length ) . ( 'b' x $b_length );
my $recce = Marpa::XS::Recognizer->new(
{ grammar => $grammar,
closures => {
'C_action' => $C_action,
'S_action' => $S_action,
'default_action' => $default_action,
}
}
);
for ( 1 .. $a_length ) { $recce->read( 'a', 'a' ); }
for ( 1 .. $b_length ) { $recce->read( 'b', 'b' ); }
my $value_ref = $recce->value();
my $value = $value_ref ? ${$value_ref} : 'No parse';
Marpa::XS::Test::is( $value, $expected{$string}, "Parse of $string" );
} ## end for my $b_length ( 0 .. $a_length )
} ## end for my $a_length ( 1 .. 4 )
1; # In case used as "do" file
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