import java.util.*;
import java.io.*;
import junit.framework.*;
import com.purpletech.util.*;

public class TokenizerTest extends TestCase
{
    public TokenizerTest(String name)
    {
	super(name);
    }

    public void testNext()
    {
	Tokenizer tk = new Tokenizer("4+5*(6+17)");
	assertEquals(tk.nextToken(), "4");
	assertEquals(tk.nextToken(), "+");
	assertEquals(tk.nextToken(), "5");
	assertEquals(tk.nextToken(), "*");
	assertEquals(tk.nextToken(), "(");
	assertEquals(tk.nextToken(), "6");
	assertEquals(tk.nextToken(), "+");
	assertEquals(tk.nextToken(), "17");
	assertEquals(tk.nextToken(), ")");
	assertNull(tk.nextToken());
    }

    public void testSpace()
    {
	Tokenizer tk = new Tokenizer("4+ 5*(6+ 17) ");
	assertEquals(tk.nextToken(), "4");
	assertEquals(tk.nextToken(), "+");
	assertEquals(tk.nextToken(), "5");
	assertEquals(tk.nextToken(), "*");
	assertEquals(tk.nextToken(), "(");
	assertEquals(tk.nextToken(), "6");
	assertEquals(tk.nextToken(), "+");
	assertEquals(tk.nextToken(), "17");
	assertEquals(tk.nextToken(), ")");
	assertNull(tk.nextToken());
    }

    public void testPushBack()
    {
	Tokenizer tk = new Tokenizer("4+5*(6+17)");
	assertEquals(tk.nextToken(), "4");
	tk.pushBack("4");
	assertEquals(tk.nextToken(), "4");
	assertEquals(tk.nextToken(), "+");
	assertEquals(tk.nextToken(), "5");
	assertEquals(tk.nextToken(), "*");
	assertEquals(tk.nextToken(), "(");
	tk.pushBack("foo");
	assertEquals(tk.nextToken(), "foo");
	assertEquals(tk.nextToken(), "6");
	assertEquals(tk.nextToken(), "+");
	assertEquals(tk.nextToken(), "17");
	assertEquals(tk.nextToken(), ")");
	assertNull(tk.nextToken());
    }
}