#!/usr/bin/perl
# Marpa::R3 is Copyright (C) 2017, Jeffrey Kegler.
#
# This module is free software; you can redistribute it and/or modify it
# under the same terms as Perl 5.10.1. For more details, see the full text
# of the licenses in the directory LICENSES.
#
# This program is distributed in the hope that it will be
# useful, but it is provided “as is” and without any express
# or implied warranties. For details, see the full text of
# of the licenses in the directory LICENSES.
# Landing page synopsis
use
5.010001;
use
strict;
use
warnings;
POSIX::setlocale(LC_ALL,
"C"
);
use
Marpa::R3::Test;
## no critic (ErrorHandling::RequireCarping);
# Marpa::R3::Display
# name: Landing page synopsis
use
Marpa::R3;
my
$dsl
=
<<'END_OF_DSL';
Calculator ::= Expression action => ::first
Factor ::= Number action => ::first
Term ::=
Term '*' Factor action => do_multiply
| Factor action => ::first
Expression ::=
Expression '+' Term action => do_add
| Term action => ::first
Number ~ digits
digits ~ [\d]+
:discard ~ whitespace
whitespace ~ [\s]+
END_OF_DSL
my
$grammar
= Marpa::R3::Scanless::G->new(
{
semantics_package
=>
'My_Actions'
,
source
=> \
$dsl
}
);
my
$input
=
'42 * 1 + 7'
;
my
$value_ref
=
$grammar
->parse( \
$input
);
sub
My_Actions::do_add {
my
(
undef
,
$values
) =
@_
;
my
(
$t1
,
undef
,
$t2
) = @{
$values
};
return
$t1
+
$t2
;
}
sub
My_Actions::do_multiply {
my
(
undef
,
$values
) =
@_
;
my
(
$t1
,
undef
,
$t2
) = @{
$values
};
return
$t1
*
$t2
;
}
# Marpa::R3::Display::End
Test::More::is( ${
$value_ref
}, 49,
'Landing page synopsis value'
);
1;
# In case used as "do" file
# Local Variables:
# mode: cperl
# cperl-indent-level: 4
# fill-column: 100
# End:
# vim: expandtab shiftwidth=4: