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#!/usr/bin/perl
# Copyright 2014 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/.
# Test of SLIF external interface
use 5.010;
use strict;
use warnings;
use Test::More tests => 1;
use lib 'inc';
use Marpa::R2::Test;
## no critic (ErrorHandling::RequireCarping);
use Marpa::R2;
my $grammar = Marpa::R2::Scanless::G->new(
{ bless_package => 'My_Nodes',
source => \(<<'END_OF_SOURCE'),
:default ::= action => ::array
:start ::= Script
Script ::= Expression+ separator => <op comma> bless => script
Expression ::=
Number bless => primary
| (<op lparen>) Expression (<op rparen>) bless => parens assoc => group
|| Expression (<op pow>) Expression bless => power assoc => right
|| Expression (<op times>) Expression bless => multiply
| Expression (<op divide>) Expression bless => divide
|| Expression (<op add>) Expression bless => add
| Expression (<op subtract>) Expression bless => subtract
Number ~ unicorn
<op comma> ~ unicorn
<op lparen> ~ unicorn
<op rparen> ~ unicorn
<op pow> ~ unicorn
<op times> ~ unicorn
<op divide> ~ unicorn
<op add> ~ unicorn
<op subtract> ~ unicorn
unicorn ~ [^\s\S]
END_OF_SOURCE
}
);
my @terminals = (
[ Number => qr/\d+/xms, "Number" ],
[ 'op pow' => qr/[\^]/xms, 'Exponentiation operator' ],
[ 'op pow' => qr/[*][*]/xms, 'Exponentiation' ], # order matters!
[ 'op times' => qr/[*]/xms, 'Multiplication operator' ], # order matters!
[ 'op divide' => qr/[\/]/xms, 'Division operator' ],
[ 'op add' => qr/[+]/xms, 'Addition operator' ],
[ 'op subtract' => qr/[-]/xms, 'Subtraction operator' ],
[ 'op lparen' => qr/[(]/xms, 'Left parenthesis' ],
[ 'op rparen' => qr/[)]/xms, 'Right parenthesis' ],
[ 'op comma' => qr/[,]/xms, 'Comma operator' ],
);
sub my_parser {
my ( $grammar, $string ) = @_;
my $recce = Marpa::R2::Scanless::R->new( { grammar => $grammar } );
# Marpa::R2::Display
# name: SLIF external read example
$recce->read( \$string, 0, 0 );
# Marpa::R2::Display::End
my $length = length $string;
pos $string = 0;
TOKEN: while (1) {
my $start_of_lexeme = pos $string;
last TOKEN if $start_of_lexeme >= $length;
next TOKEN if $string =~ m/\G\s+/gcxms; # skip whitespace
TOKEN_TYPE: for my $t (@terminals) {
my ( $token_name, $regex, $long_name ) = @{$t};
next TOKEN_TYPE if not $string =~ m/\G($regex)/gcxms;
my $lexeme = $1;
# Marpa::R2::Display
# name: SLIF lexeme_alternative() example
if ( not defined $recce->lexeme_alternative($token_name) ) {
die
qq{Parser rejected token "$long_name" at position $start_of_lexeme, before "},
substr( $string, $start_of_lexeme, 40 ), q{"};
}
next TOKEN
if $recce->lexeme_complete( $start_of_lexeme,
( length $lexeme ) );
# Marpa::R2::Display::End
} ## end TOKEN_TYPE: for my $t (@terminals)
die qq{No token found at position $start_of_lexeme, before "},
substr( $string, pos $string, 40 ), q{"};
} ## end TOKEN: while (1)
my $value_ref = $recce->value();
if ( not defined $value_ref ) {
die "No parse was found, after reading the entire input\n";
}
return ${$value_ref}->doit();
} ## end sub my_parser
my $value = my_parser( $grammar, '42*2+7/3, 42*(2+7)/3, 2**7-3, 2**(7-3)' );
Test::More::like( $value, qr/\A 86[.]3\d+ \s+ 126 \s+ 125 \s+ 16\z/xms, 'Value of parse' );
sub My_Nodes::script::doit {
my ($self) = @_;
return join q{ }, map { $_->doit() } @{$self};
}
sub My_Nodes::add::doit {
my ($self) = @_;
my ( $a, $b ) = @{$self};
return $a->doit() + $b->doit();
}
sub My_Nodes::subtract::doit {
my ($self) = @_;
my ( $a, $b ) = @{$self};
return $a->doit() - $b->doit();
}
sub My_Nodes::multiply::doit {
my ($self) = @_;
my ( $a, $b ) = @{$self};
return $a->doit() * $b->doit();
}
sub My_Nodes::divide::doit {
my ($self) = @_;
my ( $a, $b ) = @{$self};
return $a->doit() / $b->doit();
}
sub My_Nodes::primary::doit { return $_[0]->[0]; }
sub My_Nodes::parens::doit { return $_[0]->[0]->doit(); }
sub My_Nodes::power::doit {
my ($self) = @_;
my ( $a, $b ) = @{$self};
return $a->doit()**$b->doit();
}
# vim: expandtab shiftwidth=4:
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