File Coverage

lib/AI/Prolog.pm

Criterion	Covered	Total	%
statement	46	66	69.7
branch	6	16	37.5
condition			n/a
subroutine	13	18	72.2
pod	8	9	88.8
total	73	109	66.9

package AI::Prolog;
$VERSION = '0.741';    ## no critic
use strict;
use Carp qw( confess carp croak );

use Hash::Util 'lock_keys';
use Exporter::Tidy shortcuts => [qw/Parser Term Engine/];

use aliased 'AI::Prolog::Parser';
use aliased 'AI::Prolog::Term';
use aliased 'AI::Prolog::Engine';

use Text::Quote;
use Regexp::Common;

# they don't want pretty printed strings if they're using this interface
Engine->formatted(0);

# Until (and unless) we figure out the weird bug that prevents some values
# binding in the external interface, we need to stick with this as the default
Engine->raw_results(1);

sub new {
    my ( $class, $program ) = @_;
    my $self = bless {
        _prog   => Parser->consult($program),
        _query  => undef,
        _engine => undef,
    } => $class;
    lock_keys %$self;
    return $self;
}

sub do {
    my ( $self, $query ) = @_;
    $self->query($query);
    1 while $self->results;
    $self;
}

sub query {
    my ( $self, $query ) = @_;

    # make that final period optional
    $query .= '.' unless $query =~ /\.$/;
    $self->{_query} = Term->new($query);
    unless ( defined $self->{_engine} ) {

        # prime the pump
        $self->{_engine} = Engine->new( @{$self}{qw/_query _prog/} );
    }
    $self->{_engine}->query( $self->{_query} );
    return $self;
}

sub results {
    my $self = shift;
    unless ( defined $self->{_query} ) {
        croak "You can't fetch results because you have not set a query";
    }
    $self->{_engine}->results;
}

sub trace {
    my $self = shift;
    if (@_) {
        $self->{_engine}->trace(shift);
        return $self;
    }
    return $self->{_engine}->trace;
}

sub raw_results {
    my $class = shift;
    if (@_) {
        Engine->raw_results(shift);
        return $class;
    }
    return Engine->raw_results;
}

my $QUOTER;

sub quote {
    my ( $proto, $string ) = @_;
    $QUOTER = Text::Quote->new unless $QUOTER;
    return $QUOTER->quote_simple($string);
}

sub list {
    my $proto = shift;
    return
        join ", " => map { /^$RE{num}{real}$/ ? $_ : $proto->quote($_) } @_;
}

sub continue {
    my $self = shift;
    return 1 unless $self->{_engine};    # we haven't started yet!
    !$self->{_engine}->halt;
}

1;

__END__