TestAutoAST.java

/*
 * [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,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.antlr.test;

import org.junit.Ignore;
import org.junit.Test;

import static org.junit.Assert.*;

public class TestAutoAST extends BaseTest {
	protected boolean debug = false;

	@Test public void testTokenList() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : ID INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "abc 34", debug);
		assertEquals("abc 34\n", found);
	}

	@Test public void testTokenListInSingleAltBlock() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : (ID INT) ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "abc 34", debug);
		assertEquals("abc 34\n", found);
	}

	@Test public void testSimpleRootAtOuterLevel() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : ID^ INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "abc 34", debug);
		assertEquals("(abc 34)\n", found);
	}

	@Test public void testSimpleRootAtOuterLevelReverse() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : INT ID^ ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "34 abc", debug);
		assertEquals("(abc 34)\n", found);
	}

	@Test public void testBang() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ID INT! ID! INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "abc 34 dag 4532", debug);
		assertEquals("abc 4532\n", found);
	}

	@Test public void testOptionalThenRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ( ID INT )? ID^ ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a 1 b", debug);
		assertEquals("(b a 1)\n", found);
	}

	@Test public void testLabeledStringRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : v='void'^ ID ';' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "void foo;", debug);
		assertEquals("(void foo ;)\n", found);
	}

	@Test public void testWildcard() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : v='void'^ . ';' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "void foo;", debug);
		assertEquals("(void foo ;)\n", found);
	}

	@Test public void testWildcardRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : v='void' .^ ';' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "void foo;", debug);
		assertEquals("(foo void ;)\n", found);
	}

	@Test public void testWildcardRootWithLabel() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : v='void' x=.^ ';' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "void foo;", debug);
		assertEquals("(foo void ;)\n", found);
	}

    @Test public void testWildcardRootWithListLabel() throws Exception {
        String grammar =
            "grammar T;\n" +
            "options {output=AST;}\n" +
            "a : v='void' x=.^ ';' ;\n" +
            "ID : 'a'..'z'+ ;\n" +
            "INT : '0'..'9'+;\n" +
            "WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
        String found = execParser("T.g", grammar, "TParser", "TLexer",
                                  "a", "void foo;", debug);
        assertEquals("(foo void ;)\n", found);
    }

    @Test public void testWildcardBangWithListLabel() throws Exception {
        String grammar =
            "grammar T;\n" +
            "options {output=AST;}\n" +
            "a : v='void' x=.! ';' ;\n" +
            "ID : 'a'..'z'+ ;\n" +
            "INT : '0'..'9'+;\n" +
            "WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
        String found = execParser("T.g", grammar, "TParser", "TLexer",
                                  "a", "void foo;", debug);
        assertEquals("void ;\n", found);
    }

	@Test public void testRootRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ID^ INT^ ID ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a 34 c", debug);
		assertEquals("(34 a c)\n", found);
	}

	@Test public void testRootRoot2() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ID INT^ ID^ ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a 34 c", debug);
		assertEquals("(c (34 a))\n", found);
	}

	@Test public void testRootThenRootInLoop() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ID^ (INT '*'^ ID)+ ;\n" +
			"ID  : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a 34 * b 9 * c", debug);
		assertEquals("(* (* (a 34) b 9) c)\n", found);
	}

	@Test public void testNestedSubrule() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : 'void' (({;}ID|INT) ID | 'null' ) ';' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "void a b;", debug);
		assertEquals("void a b ;\n", found);
	}

	@Test public void testInvokeRule() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a  : type ID ;\n" +
			"type : {;}'int' | 'float' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "int a", debug);
		assertEquals("int a\n", found);
	}

	@Test public void testInvokeRuleAsRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a  : type^ ID ;\n" +
			"type : {;}'int' | 'float' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "int a", debug);
		assertEquals("(int a)\n", found);
	}

	@Test public void testInvokeRuleAsRootWithLabel() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a  : x=type^ ID ;\n" +
			"type : {;}'int' | 'float' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "int a", debug);
		assertEquals("(int a)\n", found);
	}

	@Test public void testInvokeRuleAsRootWithListLabel() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a  : x+=type^ ID ;\n" +
			"type : {;}'int' | 'float' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "int a", debug);
		assertEquals("(int a)\n", found);
	}

	@Test public void testRuleRootInLoop() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ID ('+'^ ID)* ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a+b+c+d", debug);
		assertEquals("(+ (+ (+ a b) c) d)\n", found);
	}

	@Test public void testRuleInvocationRuleRootInLoop() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ID (op^ ID)* ;\n" +
			"op : {;}'+' | '-' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a+b+c-d", debug);
		assertEquals("(- (+ (+ a b) c) d)\n", found);
	}

	@Test public void testTailRecursion() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"s : a ;\n" +
			"a : atom ('exp'^ a)? ;\n" +
			"atom : INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "s", "3 exp 4 exp 5", debug);
		assertEquals("(exp 3 (exp 4 5))\n", found);
	}

	@Test public void testSet() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ID|INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "abc", debug);
		assertEquals("abc\n", found);
	}

	@Test public void testSetRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ('+' | '-')^ ID ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "+abc", debug);
		assertEquals("(+ abc)\n", found);
	}

	@Test
    public void testSetRootWithLabel() throws Exception {

		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : x=('+' | '-')^ ID ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "+abc", debug);
		assertEquals("(+ abc)\n", found);
	}

	@Test public void testSetAsRuleRootInLoop() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ID (('+'|'-')^ ID)* ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a+b-c", debug);
		assertEquals("(- (+ a b) c)\n", found);
	}

	@Test public void testNotSet() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ~ID '+' INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "34+2", debug);
		assertEquals("34 + 2\n", found);
	}

	@Test public void testNotSetWithLabel() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : x=~ID '+' INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "34+2", debug);
		assertEquals("34 + 2\n", found);
	}

	@Test public void testNotSetWithListLabel() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : x=~ID '+' INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "34+2", debug);
		assertEquals("34 + 2\n", found);
	}

	@Test public void testNotSetRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ~'+'^ INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "34 55", debug);
		assertEquals("(34 55)\n", found);
	}

	@Test public void testNotSetRootWithLabel() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ~'+'^ INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "34 55", debug);
		assertEquals("(34 55)\n", found);
	}

	@Test public void testNotSetRootWithListLabel() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ~'+'^ INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "34 55", debug);
		assertEquals("(34 55)\n", found);
	}

	@Test public void testNotSetRuleRootInLoop() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : INT (~INT^ INT)* ;\n" +
			"blort : '+' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "3+4+5", debug);
		assertEquals("(+ (+ 3 4) 5)\n", found);
	}

	@Test public void testTokenLabelReuse() throws Exception {
		// check for compilation problem due to multiple defines
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : id=ID id=ID {System.out.print(\"2nd id=\"+$id.text+';');} ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a b", debug);
		assertEquals("2nd id=b;a b\n", found);
	}

	@Test public void testTokenLabelReuse2() throws Exception {
		// check for compilation problem due to multiple defines
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : id=ID id=ID^ {System.out.print(\"2nd id=\"+$id.text+';');} ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a b", debug);
		assertEquals("2nd id=b;(b a)\n", found);
	}

	@Test public void testTokenListLabelReuse() throws Exception {
		// check for compilation problem due to multiple defines
		// make sure ids has both ID tokens
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ids+=ID ids+=ID {System.out.print(\"id list=\"+$ids+';');} ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a b", debug);
		String expecting = "id list=[[@0,0:0='a',<4>,1:0], [@2,2:2='b',<4>,1:2]];a b\n";
		assertEquals(expecting, found);
	}

	@Test public void testTokenListLabelReuse2() throws Exception {
		// check for compilation problem due to multiple defines
		// make sure ids has both ID tokens
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ids+=ID^ ids+=ID {System.out.print(\"id list=\"+$ids+';');} ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a b", debug);
		String expecting = "id list=[[@0,0:0='a',<4>,1:0], [@2,2:2='b',<4>,1:2]];(a b)\n";
		assertEquals(expecting, found);
	}

	@Test public void testTokenListLabelRuleRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : id+=ID^ ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a", debug);
		assertEquals("a\n", found);
	}

	@Test public void testTokenListLabelBang() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : id+=ID! ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a", debug);
		assertEquals("", found);
	}

	@Test public void testRuleListLabel() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : x+=b x+=b {" +
			"Tree t=(Tree)$x.get(1);" +
			"System.out.print(\"2nd x=\"+t.toStringTree()+';');} ;\n" +
			"b : ID;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a b", debug);
		assertEquals("2nd x=b;a b\n", found);
	}

	@Test public void testRuleListLabelRuleRoot() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : ( x+=b^ )+ {" +
			"System.out.print(\"x=\"+((CommonTree)$x.get(1)).toStringTree()+';');} ;\n" +
			"b : ID;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a b", debug);
		assertEquals("x=(b a);(b a)\n", found);
	}

	@Test public void testRuleListLabelBang() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : x+=b! x+=b {" +
			"System.out.print(\"1st x=\"+((CommonTree)$x.get(0)).toStringTree()+';');} ;\n" +
			"b : ID;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a b", debug);
		assertEquals("1st x=a;b\n", found);
	}

	@Test public void testComplicatedMelange() throws Exception {
		// check for compilation problem
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a : A b=B b=B c+=C c+=C D {String s = $D.text;} ;\n" +
			"A : 'a' ;\n" +
			"B : 'b' ;\n" +
			"C : 'c' ;\n" +
			"D : 'd' ;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "a", "a b b c c d", debug);
		assertEquals("a b b c c d\n", found);
	}

	@Test public void testReturnValueWithAST() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : ID b {System.out.println($b.i);} ;\n" +
			"b returns [int i] : INT {$i=Integer.parseInt($INT.text);} ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "abc 34", debug);
		assertEquals("34\nabc 34\n", found);
	}

	@Test public void testSetLoop() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options { output=AST; }\n" +
			"r : (INT|ID)+ ; \n" +
			"ID : 'a'..'z' + ;\n" +
			"INT : '0'..'9' +;\n" +
			"WS: (' ' | '\\n' | '\\t')+ {$channel = HIDDEN;};\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer",
								  "r", "abc 34 d", debug);
		assertEquals("abc 34 d\n", found);
	}

	@Test public void testExtraTokenInSimpleDecl() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"decl : type^ ID '='! INT ';'! ;\n" +
			"type : 'int' | 'float' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "decl", "int 34 x=1;", debug);
		assertEquals("line 1:4 extraneous input '34' expecting ID\n", this.stderrDuringParse);
		assertEquals("(int x 1)\n", found); // tree gets correct x and 1 tokens
	}

	@Test public void testMissingIDInSimpleDecl() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"tokens {EXPR;}\n" +
			"decl : type^ ID '='! INT ';'! ;\n" +
			"type : 'int' | 'float' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "decl", "int =1;", debug);
		assertEquals("line 1:4 missing ID at '='\n", this.stderrDuringParse);
		assertEquals("(int <missing ID> 1)\n", found); // tree gets invented ID token
	}

	@Test public void testMissingSetInSimpleDecl() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"tokens {EXPR;}\n" +
			"decl : type^ ID '='! INT ';'! ;\n" +
			"type : 'int' | 'float' ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "decl", "x=1;", debug);
		assertEquals("line 1:0 mismatched input 'x' expecting set null\n", this.stderrDuringParse);
		assertEquals("(<error: x> x 1)\n", found); // tree gets invented ID token
	}

	@Test public void testMissingTokenGivesErrorNode() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : ID INT ;\n" + // follow is EOF
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "abc", debug);
		assertEquals("line 1:3 missing INT at '<EOF>'\n", this.stderrDuringParse);
		assertEquals("abc <missing INT>\n", found);
	}

	@Test public void testMissingTokenGivesErrorNodeInInvokedRule() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : b ;\n" +
			"b : ID INT ;\n" + // follow should see EOF
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "abc", debug);
		assertEquals("line 1:3 mismatched input '<EOF>' expecting INT\n", this.stderrDuringParse);
		assertEquals("<mismatched token: [@1,3:3='<EOF>',<-1>,1:3], resync=abc>\n", found);
	}

	@Test public void testExtraTokenGivesErrorNode() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : b c ;\n" +
			"b : ID ;\n" +
			"c : INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "abc ick 34", debug);
		assertEquals("line 1:4 extraneous input 'ick' expecting INT\n", this.stderrDuringParse);
		assertEquals("abc 34\n", found);
	}

	@Test public void testMissingFirstTokenGivesErrorNode() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : ID INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "34", debug);
		assertEquals("line 1:0 missing ID at '34'\n", this.stderrDuringParse);
		assertEquals("<missing ID> 34\n", found);
	}

	@Test public void testMissingFirstTokenGivesErrorNode2() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : b c ;\n" +
			"b : ID ;\n" +
			"c : INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "34", debug);
		// finds an error at the first token, 34, and re-syncs.
		// re-synchronizing does not consume a token because 34 follows
		// ref to rule b (start of c). It then matches 34 in c.
		assertEquals("line 1:0 missing ID at '34'\n", this.stderrDuringParse);
		assertEquals("<missing ID> 34\n", found);
	}

	@Test public void testNoViableAltGivesErrorNode() throws Exception {
		String grammar =
			"grammar foo;\n" +
			"options {output=AST;}\n" +
			"a : b | c ;\n" +
			"b : ID ;\n" +
			"c : INT ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"S : '*' ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("foo.g", grammar, "fooParser", "fooLexer",
								  "a", "*", debug);
		assertEquals("line 1:0 no viable alternative at input '*'\n", this.stderrDuringParse);
		assertEquals("<unexpected: [@0,0:0='*',<6>,1:0], resync=*>\n", found);
	}


	// S U P P O R T

	private void _test() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {output=AST;}\n" +
			"a :  ;\n" +
			"ID : 'a'..'z'+ ;\n" +
			"INT : '0'..'9'+;\n" +
			"WS : (' '|'\\n') {$channel=HIDDEN;} ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", "abc 34", debug);
		assertEquals("\n", found);
	}

}