/*
* [The "BSD license"]
* Copyright (c) 2010 Terence Parr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.antlr.test;
import org.antlr.runtime.*;
import org.antlr.tool.Grammar;
import org.antlr.tool.Interpreter;
import org.junit.Test;
import static org.junit.Assert.*;
/** This actually tests new (12/4/09) buffered but on-demand fetching stream */
public class TestCommonTokenStream extends BaseTest {
@Test public void testFirstToken() throws Exception {
Grammar g = new Grammar(
"lexer grammar t;\n"+
"ID : 'a'..'z'+;\n" +
"INT : '0'..'9'+;\n" +
"SEMI : ';';\n" +
"ASSIGN : '=';\n" +
"PLUS : '+';\n" +
"MULT : '*';\n" +
"WS : ' '+;\n");
// Tokens: 012345678901234567
// Input: x = 3 * 0 + 2 * 0;
CharStream input = new ANTLRStringStream("x = 3 * 0 + 2 * 0;");
Interpreter lexEngine = new Interpreter(g, input);
BufferedTokenStream tokens = new BufferedTokenStream(lexEngine);
String result = tokens.LT(1).getText();
String expecting = "x";
assertEquals(expecting, result);
}
@Test public void test2ndToken() throws Exception {
Grammar g = new Grammar(
"lexer grammar t;\n"+
"ID : 'a'..'z'+;\n" +
"INT : '0'..'9'+;\n" +
"SEMI : ';';\n" +
"ASSIGN : '=';\n" +
"PLUS : '+';\n" +
"MULT : '*';\n" +
"WS : ' '+;\n");
// Tokens: 012345678901234567
// Input: x = 3 * 0 + 2 * 0;
CharStream input = new ANTLRStringStream("x = 3 * 0 + 2 * 0;");
Interpreter lexEngine = new Interpreter(g, input);
BufferedTokenStream tokens = new BufferedTokenStream(lexEngine);
String result = tokens.LT(2).getText();
String expecting = " ";
assertEquals(expecting, result);
}
@Test public void testCompleteBuffer() throws Exception {
Grammar g = new Grammar(
"lexer grammar t;\n"+
"ID : 'a'..'z'+;\n" +
"INT : '0'..'9'+;\n" +
"SEMI : ';';\n" +
"ASSIGN : '=';\n" +
"PLUS : '+';\n" +
"MULT : '*';\n" +
"WS : ' '+;\n");
// Tokens: 012345678901234567
// Input: x = 3 * 0 + 2 * 0;
CharStream input = new ANTLRStringStream("x = 3 * 0 + 2 * 0;");
Interpreter lexEngine = new Interpreter(g, input);
BufferedTokenStream tokens = new BufferedTokenStream(lexEngine);
int i = 1;
Token t = tokens.LT(i);
while ( t.getType()!=Token.EOF ) {
i++;
t = tokens.LT(i);
}
tokens.LT(i++); // push it past end
tokens.LT(i++);
String result = tokens.toString();
String expecting = "x = 3 * 0 + 2 * 0;";
assertEquals(expecting, result);
}
@Test public void testCompleteBufferAfterConsuming() throws Exception {
Grammar g = new Grammar(
"lexer grammar t;\n"+
"ID : 'a'..'z'+;\n" +
"INT : '0'..'9'+;\n" +
"SEMI : ';';\n" +
"ASSIGN : '=';\n" +
"PLUS : '+';\n" +
"MULT : '*';\n" +
"WS : ' '+;\n");
// Tokens: 012345678901234567
// Input: x = 3 * 0 + 2 * 0;
CharStream input = new ANTLRStringStream("x = 3 * 0 + 2 * 0;");
Interpreter lexEngine = new Interpreter(g, input);
BufferedTokenStream tokens = new BufferedTokenStream(lexEngine);
Token t = tokens.LT(1);
while ( t.getType()!=Token.EOF ) {
tokens.consume();
t = tokens.LT(1);
}
tokens.consume();
tokens.LT(1); // push it past end
tokens.consume();
tokens.LT(1);
String result = tokens.toString();
String expecting = "x = 3 * 0 + 2 * 0;";
assertEquals(expecting, result);
}
@Test public void testLookback() throws Exception {
Grammar g = new Grammar(
"lexer grammar t;\n"+
"ID : 'a'..'z'+;\n" +
"INT : '0'..'9'+;\n" +
"SEMI : ';';\n" +
"ASSIGN : '=';\n" +
"PLUS : '+';\n" +
"MULT : '*';\n" +
"WS : ' '+;\n");
// Tokens: 012345678901234567
// Input: x = 3 * 0 + 2 * 0;
CharStream input = new ANTLRStringStream("x = 3 * 0 + 2 * 0;");
Interpreter lexEngine = new Interpreter(g, input);
BufferedTokenStream tokens = new BufferedTokenStream(lexEngine);
tokens.consume(); // get x into buffer
Token t = tokens.LT(-1);
assertEquals("x", t.getText());
tokens.consume();
tokens.consume(); // consume '='
t = tokens.LT(-3);
assertEquals("x", t.getText());
t = tokens.LT(-2);
assertEquals(" ", t.getText());
t = tokens.LT(-1);
assertEquals("=", t.getText());
}
@Test public void testOffChannel() throws Exception {
TokenSource lexer = // simulate input " x =34 ;\n"
new TokenSource() {
int i = 0;
Token[] tokens = {
new CommonToken(1," "),
new CommonToken(1,"x"),
new CommonToken(1," "),
new CommonToken(1,"="),
new CommonToken(1,"34"),
new CommonToken(1," "),
new CommonToken(1," "),
new CommonToken(1,";"),
new CommonToken(1,"\n"),
new CommonToken(Token.EOF,"")
};
{
tokens[0].setChannel(Lexer.HIDDEN);
tokens[2].setChannel(Lexer.HIDDEN);
tokens[5].setChannel(Lexer.HIDDEN);
tokens[6].setChannel(Lexer.HIDDEN);
tokens[8].setChannel(Lexer.HIDDEN);
}
@Override
public Token nextToken() {
return tokens[i++];
}
@Override
public String getSourceName() { return "test"; }
};
CommonTokenStream tokens = new CommonTokenStream(lexer);
assertEquals("x", tokens.LT(1).getText()); // must skip first off channel token
tokens.consume();
assertEquals("=", tokens.LT(1).getText());
assertEquals("x", tokens.LT(-1).getText());
tokens.consume();
assertEquals("34", tokens.LT(1).getText());
assertEquals("=", tokens.LT(-1).getText());
tokens.consume();
assertEquals(";", tokens.LT(1).getText());
assertEquals("34", tokens.LT(-1).getText());
tokens.consume();
assertEquals(Token.EOF, tokens.LA(1));
assertEquals(";", tokens.LT(-1).getText());
assertEquals("34", tokens.LT(-2).getText());
assertEquals("=", tokens.LT(-3).getText());
assertEquals("x", tokens.LT(-4).getText());
}
}