CDiscrete.java

/*
 * @cond LICENSE
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 * # published by the Free Software Foundation, either version 3 of the                 #
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package org.lightjason.agentspeak.consistency.metric;

import org.lightjason.agentspeak.language.ITerm;

import java.util.Collection;
import java.util.HashSet;
import java.util.stream.Collectors;
import java.util.stream.Stream;


/**
 * generic discrete metric
 *
 * @see http://mathworld.wolfram.com/DiscreteMetric.html
 */
public final class CDiscrete implements IMetric
{

    @Override
    public final Double apply( final Stream<? extends ITerm> p_first, final Stream<? extends ITerm> p_second )
    {
        final Collection<ITerm> l_first = p_first.collect( Collectors.toCollection( HashSet<ITerm>::new ) );
        final Collection<ITerm> l_second = p_second.collect( Collectors.toCollection( HashSet<ITerm>::new ) );

        return ( l_first.containsAll( l_second ) ) && ( l_second.containsAll( l_first ) ) ? 0.0 : 1.0;
    }

}