VariableCollectorTest.java

package aima.test.core.unit.logic.fol;

import java.util.Set;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import aima.core.logic.fol.VariableCollector;
import aima.core.logic.fol.domain.DomainFactory;
import aima.core.logic.fol.parsing.FOLParser;
import aima.core.logic.fol.parsing.ast.Variable;

/**
 * @author Ravi Mohan
 * 
 */
public class VariableCollectorTest {

	FOLParser parser;

	VariableCollector vc;

	@Before
	public void setUp() {
		parser = new FOLParser(DomainFactory.crusadesDomain());
		vc = new VariableCollector();
	}

	@Test
	public void testSimplepredicate() {
		Set<Variable> variables = vc.collectAllVariables(parser
				.parse("King(x)"));
		Assert.assertEquals(1, variables.size());
		Assert.assertTrue(variables.contains(new Variable("x")));
	}

	@Test
	public void testMultipleVariables() {
		Set<Variable> variables = vc.collectAllVariables(parser
				.parse("BrotherOf(x) = EnemyOf(y)"));
		Assert.assertEquals(2, variables.size());
		Assert.assertTrue(variables.contains(new Variable("x")));
		Assert.assertTrue(variables.contains(new Variable("y")));
	}

	@Test
	public void testQuantifiedVariables() {
		// Note: Should collect quantified variables
		// even if not mentioned in clause.
		Set<Variable> variables = vc.collectAllVariables(parser
				.parse("FORALL x,y,z (BrotherOf(x) = EnemyOf(y))"));
		Assert.assertEquals(3, variables.size());
		Assert.assertTrue(variables.contains(new Variable("x")));
		Assert.assertTrue(variables.contains(new Variable("y")));
		Assert.assertTrue(variables.contains(new Variable("z")));
	}
}