ProbContextFreeGrammarTest.java

package aima.test.core.unit.nlp.parse;

import static org.junit.Assert.*;

import java.util.ArrayList;
import java.util.Arrays;

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

import aima.core.nlp.data.grammars.ProbContextFreeExamples;
import aima.core.nlp.parsing.grammars.ProbUnrestrictedGrammar;
import aima.core.nlp.parsing.grammars.Rule;

public class ProbContextFreeGrammarTest {

	ProbUnrestrictedGrammar g;
	ProbUnrestrictedGrammar cfG;
	
	@Before
	public void setup() {
		g = new ProbUnrestrictedGrammar();
		cfG = ProbContextFreeExamples.buildWumpusGrammar();
	}
	
	@Test
	public void testValidRule() {
		// This rule is a valid Context-Free rule
		Rule validR   = new Rule( new ArrayList<String>(Arrays.asList("W")), 
								  new ArrayList<String>(Arrays.asList("a","s")), (float)0.5);
		// This rule is of correct form but not a context-free rule
		Rule invalidR  = new Rule( new ArrayList<String>(Arrays.asList("W","A")), null , (float)0.5);
		assertFalse( cfG.validRule(invalidR));
		assertTrue(  cfG.validRule(validR));
	}

}