AI-Prolog

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data/sleepy.pro  view on Meta::CPAN

/* "Sleepy" -- a sample adventure game, by David Matuszek. */

% http://www.csc.vill.edu/~dmatusze/resources/prolog/sleepy.html
/* In standard Prolog, all predicates are "dynamic": they
   can be changed during execution. SWI-Prolog requires such
   predicates to be specially marked. */

% :- dynamic at/2, i_am_at/1, i_am_holding/1, alive/1,
%           lit/1, visible_object/1.

/* This routine is purely for debugging purposes. */

%dump :- listing(at), listing(i_am_at), listing(i_am_holding),
%        listing(alive), listing(lit), listing(visible_object).

/* This defines my current location. */

i_am_at(bedroom).

i_am_holding(nothing).

data/sleepy.pro  view on Meta::CPAN

    /* Have flyswatter, room is lit, fly is here and alive. */

swat :-
    buzz_off,
    print('The fly escapes into the other room.'), nl.

swat :-
    print('Success! You killed that pesky fly!'), nl,
    retract(alive(fly)).

swat :- /* For debugging... */
    print('You must have forgotten a case!', nl).

make_visible(X) :-
    visible_object(X).

make_visible(X) :-
    assert(visible_object(X)).

buzz_off :-
    at(fly, bedroom),

lib/AI/Prolog/Builtins.pod  view on Meta::CPAN

=back

=head1 MATH

Since version .70, math is fully available in C<AI::Prolog>.  Note that math is
implemented via the
L<AI::Prolog::Parser::PreProcessor::Math|AI::Prolog::Parser::PreProcessor::Math>
module.  This module rewrites Prolog math to an internal, predicate-based form
with the L<AI::Prolog::Parser|AI::Prolog::Parser> can parse.  This may cause
confusion when debugging.

 X is 5 + 7.
 % internally converted to 
 % is(X, plus(5, 7)).

The math predicates are officially deprecated and I<cannot> be used in the same
expression with regular Prolog math.  

Number may be integers, floats, doubles, etc.  A number that starts with a
minus sign (-) is considered negative.  No number may end in a decimal point as

lib/AI/Prolog/Parser.pm  view on Meta::CPAN

package AI::Prolog::Parser;
$REVISION = '$Id: Parser.pm,v 1.9 2005/08/06 23:28:40 ovid Exp $';

$VERSION = '0.10';
use strict;
use warnings;
use Carp qw( confess croak );
use Regexp::Common;
use Hash::Util 'lock_keys';

# debugging stuff
use Clone;
use Text::Balanced qw/extract_quotelike extract_delimited/;

use aliased 'AI::Prolog::Engine';
use aliased 'AI::Prolog::KnowledgeBase';
use aliased 'AI::Prolog::Parser::PreProcessor';
use aliased 'AI::Prolog::Term';
use aliased 'AI::Prolog::Term::Number';
use aliased 'AI::Prolog::TermList';
use aliased 'AI::Prolog::TermList::Clause';

lib/AI/Prolog/Term.pm  view on Meta::CPAN

        return $self->ref->occurs1($var) if $self->{deref};
        for my $i ( 0 .. $self->arity - 1 ) {
            return 1 if $self->{args}[$i]->occurs1($var);
        }
    }
    else {
        return $self->varid == $var;
    }
}

# used internally for debugging
sub _dumpit {
    local $^W;
    my $self = shift;
    my $indent = shift || '';
    print( $indent . "source:  ", $self->{source} );
    print( $indent . "bound:  ", ( $self->{bound} ? 'true' : 'false' ) );
    print( $indent . "functor:  ", ( $self->{functor} || 'null' ) );
    if ( !$self->{ref} ) {
        print( $indent . "ref:  null" );
    }

lib/AI/Prolog/TermList.pm  view on Meta::CPAN

        $self->{next} = shift;
        return $self;
    }
    return $self->{next};
}

sub next_clause {
    my $self = shift;
    if (@_) {

        # XXX debug
        my $next_clause = shift;
        no warnings 'uninitialized';
        if ( $next_clause eq $self ) {
            confess("Trying to assign a termlist as its own successor");
        }
        $self->{next_clause} = $next_clause;
        return $self;
    }
    return $self->{next_clause};
}

lib/AI/Prolog/TermList/Step.pm  view on Meta::CPAN

1;
__END__

=head1 NAME

AI::Prolog::TermList::Step - Perl implementation of Prolog "step" mechanism.

=head1 SYNOPSIS

No user serviceable parts inside.  You should never be seeing this.  This is
a debugging tool.

=head1 DESCRIPTION

See L<AI::Prolog|AI::Prolog> for more information.  If you must know more,
there are plenty of comments sprinkled through the code.

=head1 SEE ALSO

L<AI::Prolog>