IExpression.java

/*
 * @cond LICENSE
 * ######################################################################################
 * # LGPL License                                                                       #
 * #                                                                                    #
 * # This file is part of the LightJason AgentSpeak(L++)                                #
 * # Copyright (c) 2015-19, LightJason (info@lightjason.org)                            #
 * # This program is free software: you can redistribute it and/or modify               #
 * # it under the terms of the GNU Lesser General Public License as                     #
 * # published by the Free Software Foundation, either version 3 of the                 #
 * # License, or (at your option) any later version.                                    #
 * #                                                                                    #
 * # This program is distributed in the hope that it will be useful,                    #
 * # but WITHOUT ANY WARRANTY; without even the implied warranty of                     #
 * # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the                      #
 * # GNU Lesser General Public License for more details.                                #
 * #                                                                                    #
 * # You should have received a copy of the GNU Lesser General Public License           #
 * # along with this program. If not, see http://www.gnu.org/licenses/                  #
 * ######################################################################################
 * @endcond
 */

package org.lightjason.agentspeak.language.execution.expression;

import org.lightjason.agentspeak.language.CRawTerm;
import org.lightjason.agentspeak.language.ITerm;
import org.lightjason.agentspeak.language.execution.IContext;
import org.lightjason.agentspeak.language.execution.IExecution;
import org.lightjason.agentspeak.language.fuzzy.CFuzzyValue;
import org.lightjason.agentspeak.language.fuzzy.IFuzzyValue;
import org.lightjason.agentspeak.language.variable.IVariable;

import javax.annotation.Nonnull;
import java.util.List;
import java.util.stream.Stream;


/**
 * expression interface
 */
public interface IExpression extends IExecution
{
    /**
     * empty expression, is always true
     */
    IExpression EMPTY = new IExpression()
    {
        /**
         * serial id
         */
        private static final long serialVersionUID = 1051229233293816991L;

        @Nonnull
        @Override
        public final IFuzzyValue<Boolean> execute( final boolean p_parallel, @Nonnull final IContext p_context,
                                                   @Nonnull final List<ITerm> p_argument, @Nonnull final List<ITerm> p_return
        )
        {
            p_return.add( CRawTerm.from( true ) );
            return CFuzzyValue.from( true );
        }

        @Nonnull
        @Override
        public final Stream<IVariable<?>> variables()
        {
            return Stream.empty();
        }

        @Override
        public final String toString()
        {
            return "true";
        }
    };


}