:- object(state_space,
instantiates(class),
specializes(object)).
:- info([
version is 1.0,
author is 'Paulo Moura',
date is 1998/3/23,
comment is 'State space description predicates.']).
:- public(initial_state/1).
:- mode(initial_state(?nonvar), one_or_more).
:- info(initial_state/1,
[comment is 'Initial state.',
argnames is ['State']]).
:- public(initial_state/2).
:- mode(initial_state(?atom, ?nonvar), zero_or_more).
:- info(initial_state/2,
[comment is 'Named initial state.',
argnames is ['Name', 'State']]).
:- public(next_state/2).
:- mode(next_state(+nonvar, -nonvar), zero_or_more).
:- info(next_state/2,
[comment is 'Generates a state sucessor.',
argnames is ['State', 'Next']]).
:- public(goal_state/1).
:- mode(goal_state(?nonvar), one_or_more).
:- info(goal_state/1,
[comment is 'Goal state.',
:- public(goal_state/2).
:- mode(goal_state(?atom, ?nonvar), zero_or_more).
:- info(goal_state/2,
[comment is 'Named goal state.',
:- public(print_state/1).
:- mode(print_state(+nonvar), one).
:- info(print_state/1,
[comment is 'Pretty print state.',
:- public(print_path/1).
:- mode(print_path(+list), one).
:- info(print_path/1,
[comment is 'Pretty print a path (list of states).',
argnames is ['Path']]).
initial_state(State) :-
::initial_state(_, State).
goal_state(State) :-
::goal_state(_, State).
print_state(State) :-
writeq(State), nl.
print_path([]).
print_path([State| States]) :-
::print_state(State),
print_path(States).
:- end_object.
