package org.archstudio.prolog.op.iso;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.archstudio.prolog.engine.ProofContext;
import org.archstudio.prolog.engine.UnificationEngine;
import org.archstudio.prolog.op.Executable;
import org.archstudio.prolog.term.ComplexTerm;
import org.archstudio.prolog.term.ConstantTerm;
import org.archstudio.prolog.term.ListTerm;
import org.archstudio.prolog.term.Term;
import org.archstudio.prolog.term.VariableTerm;
public class IsAtomic extends ComplexTerm implements Executable {
public IsAtomic(String name, List<? extends Term> terms) {
super(name, 1, terms);
}
@Override
public Iterable<Map<VariableTerm, Term>> execute(ProofContext proofContext, UnificationEngine unificationEngine,
Term source, Map<VariableTerm, Term> variables) {
Term t = getTerm(0).resolve(proofContext, variables);
if (t instanceof ConstantTerm || t instanceof ListTerm && ((ListTerm) t).isEmpty()) {
return Collections.singleton(variables);
}
return Collections.emptyList();
}
}