AI-Prolog
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Revision history for Perl extension AI::Prolog.
0.740 2008-11-12
t/60aiprolog.t fixed number of planned tests (RT#41154).
Fixed dependencies in some tests.
Fixed HEAD|TAIL results bug. Added test (RT#64942).
(Should raw_results(0) be default? or keep backward compat?).
0.740 2008-11-12
t/60aiprolog.t loads modules in the right order now
0.739 2007-05-04
Explicitly import Carp. This fixes a bug exposed by
warnings.pm. Thanks to Andreas Koenig for sending in the failing test.
0.738 2007-05-01
Several test modules are now optional by virtue of a patch by
Added Test::Exception to the PREREQ_PM (thanks to rjray for
pointing that out).
Updated the docs and examples.
0.65 Wed May 11, 2005
Added Term::ReadLine support to aiprolog shell.
Added Term::ReadKey support to aiprolog shell.
Minor doc corrections.
0.64 Mon May 09, 2005
Change default behavior to AI::Prolog->raw_results(1).
Added quote() method to allow Perl variables to be quoted
and used at Prolog terms.
Added list() method to allow a Perl list to be turned into
a Prolog list.
0.63 Wed May 04, 2005
Allow parser to properly handle positive and negative numbers
and decimal points.
Added pow(X,Y).
Eliminated studlyCaps methods.
bin/aiprolog view on Meta::CPAN
C<aiprolog> is a simple prolog shell using L<AI::Prolog> as the backend.
See the documentation for more detail on the Prolog features that L<AI::Prolog>
currently accepts.
=head2 Commands
Commands specific to aiprolog shell:
"% more" -- enables prompting for more results (default)
"% no more" -- disables prompting for more results
"% nomore" -- same as "no more"
"% halt" -- stops the shell
"% help" -- display this message
Note that the percent sign must preceed the command. The percent sign
indicates a Prolog comment. Without that, aiprolog will think you're trying to
execute a prolog command.
aiprolog-specific commands are case-insensitive.
lib/AI/Prolog.pm view on Meta::CPAN
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;
lib/AI/Prolog.pm view on Meta::CPAN
AI::Prolog->raw_results(1);
$prolog->query('steals(badguy, STUFF, VICTIM)');
while (my $r = $prolog->results) {
# do stuff with $r in the form:
# ['steals', 'badguy', $STUFF, $VICTIM]
}
Calling C<raw_results> without an argument returns the current C<raw_results>
value.
This is the default behavior.
=head2 C<quote($string)>.
This method quotes a Perl string to allow C<AI::Prolog> to treat it as a proper
Prolog term (and not worry about it accidentally being treated as a variable if
it begins with an upper-case letter).
my $perl6 = AI::Prolog->quote('Perl 6'); # returns 'Perl 6' (with quotes)
$prolog->query(qq'can_program("ovid",$perl6).');
lib/AI/Prolog.pm view on Meta::CPAN
=item * Tutorial.
=item * Data structure cookbook.
=item * Better error reporting.
=back
=head1 EXPORT
None by default. However, for convenience, you can choose ":all" functions to
be exported. That will provide you with C<Term>, C<Parser>, and C<Engine>
classes. This is not recommended and most support and documentation will now
target the C<AI::Prolog> interface.
If you choose not to export the functions, you may use the fully qualified
package names instead:
use AI::Prolog;
my $database = AI::Prolog::Parser->consult(<<'END_PROLOG');
append([], X, X).
lib/AI/Prolog/Article.pod view on Meta::CPAN
=item Programming in Prolog
http://portal.acm.org/citation.cfm?id=39071
This book is sometimes referred to simply as "Clocksin/Mellish". First
published in the early 80s, this is the book that brought Prolog into the
mainstream.
=item The Art of Prolog
htp://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=8327
This excellent MIT textbook is very in-depth and covers "proving" Prolog
programming, second-order logic, grammars, and many working examples.
=back
=head1 Credits
Many thanks to Rebekah Golden, Danny Werner and David Wheeler for their
excellents comments and insights.
lib/AI/Prolog/Engine.pm view on Meta::CPAN
%if(X, _ , No) :- seq(No).
%if(X, Yes) :- seq(X), !, seq(Yes).
%if(X, _ ).
%or(X,Y) :- seq(X).
%or(X,Y) :- seq(Y).
once(X) :- X , !.
END_PROG
$self->_adding_builtins(0);
};
if ($@) {
croak("Engine->new failed. Cannot parse default program: $@");
}
$self->{_retract_clause} = $self->{_db}->get("retract/1");
$self->{_goal}->resolve( $self->{_db} );
return $self;
}
sub query {
my ( $self, $query ) = @_;
$self->{_stack} = [];
$self->{_run_called} = undef;
lib/AI/Prolog/Engine.pm view on Meta::CPAN
while (my $results = $engine->results) {
print $results, $/;
}
The need to have a query at the same time you're instantiating the engine is a
bit of a drawback based upon the original W-Prolog work. I will likely remove
this drawback in the future.
=head2 C<formatted([$boolean])>
The default value of C<formatted> is true. This method, if passed a true
value, will cause C<results> to return a nicely formatted string representing
the output of the program. This string will loosely correspond with the
expected output of a Prolog program.
If false, all calls to C<result> will return Perl data structures instead of
nicely formatted output.
If called with no arguments, this method returns the current C<formatted>
value.
Engine->formatted(1); # turn on formatting
Engine->formatted(0); # turn off formatting (default)
if (Engine->formatted) {
# test if formatting is enabled
}
B<Note>: if you choose to use the L<AI::Prolog|AI::Prolog> interface instead of
interacting directly with this class, that interface will set C<formatted> to
false. You will have to set it back in your code if you do not wish this
behavior:
use AI::Prolog;
my $logic = AI::Prolog->new($prog_text);
$logic->query($query_text);
AI::Logic::Engine->formatted(1); # if you want formatted to true
while (my $results = $logic->results) {
print "$results\n";
}
=head2 C<raw_results([$boolean])>
The default value of C<raw_results> is false. Setting this property to a true
value automatically sets C<formatted> to false. C<results> will return the raw
data structures generated by questions when this property is true.
Engine->raw_results(1); # turn on raw results
Engine->raw_results(0); # turn off raw results (default)
if (Engine->raw_results) {
# test if raw results is enabled
}
=head2 C<trace($boolean)>
Set this to a true value to turn on tracing. This will trace through the
engine's goal satisfaction process while it's running. This is very slow.
( run in 0.364 second using v1.01-cache-2.11-cpan-0a6323c29d9 )