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The ANTLR 4 grammar compiler.
There is a newer version: 4.9.0
/*
 * Copyright (c) 2012 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD-3-Clause license that
 * can be found in the LICENSE.txt file in the project root.
 */

/** The definitive ANTLR v3 tree grammar to walk/visit ANTLR v4 grammars.
 *  Parses trees created by ANTLRParser.g.
 *
 *  Rather than have multiple tree grammars, one for each visit, I'm
 *  creating this generic visitor that knows about context. All of the
 *  boilerplate pattern recognition is done here. Then, subclasses can
 *  override the methods they care about. This prevents a lot of the same
 *  context tracking stuff like "set current alternative for current
 *  rule node" that is repeated in lots of tree filters.
 */
tree grammar GrammarTreeVisitor;
options {
	language      = Java;
	tokenVocab    = ANTLRParser;
	ASTLabelType  = GrammarAST;
}

// Include the copyright in this source and also the generated source
@header {
/*
 * Copyright (c) 2012 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD-3-Clause license that
 * can be found in the LICENSE.txt file in the project root.
 */
package org.antlr.v4.parse;
import org.antlr.v4.Tool;
import org.antlr.v4.tool.*;
import org.antlr.v4.tool.ast.*;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
}

@members {
public String grammarName;
public GrammarAST currentRuleAST;
public String currentModeName = LexerGrammar.DEFAULT_MODE_NAME;
public String currentRuleName;
public GrammarAST currentOuterAltRoot;
public int currentOuterAltNumber = 1; // 1..n
public int rewriteEBNFLevel = 0;

public GrammarTreeVisitor() { this(null); }

// Should be abstract but can't make gen'd parser abstract;
// subclasses should implement else everything goes to stderr!
public ErrorManager getErrorManager() { return null; }

public void visitGrammar(GrammarAST t) { visit(t, "grammarSpec"); }
public void visit(GrammarAST t, String ruleName) {
	CommonTreeNodeStream nodes = new CommonTreeNodeStream(new GrammarASTAdaptor(), t);
	setTreeNodeStream(nodes);
	try {
		Method m = getClass().getMethod(ruleName);
		m.invoke(this);
	}
	catch (Throwable e) {
		ErrorManager errMgr = getErrorManager();
		if ( e instanceof InvocationTargetException ) {
			e = e.getCause();
		}

		if ( errMgr==null ) {
			System.err.println("can't find rule "+ruleName+
							   " or tree structure error: "+t.toStringTree()
							   );
			e.printStackTrace(System.err);
		}
		else errMgr.toolError(ErrorType.INTERNAL_ERROR, e);
	}
}

public void discoverGrammar(GrammarRootAST root, GrammarAST ID) { }
public void finishPrequels(GrammarAST firstPrequel) { }
public void finishGrammar(GrammarRootAST root, GrammarAST ID) { }

public void grammarOption(GrammarAST ID, GrammarAST valueAST) { }
public void ruleOption(GrammarAST ID, GrammarAST valueAST) { }
public void blockOption(GrammarAST ID, GrammarAST valueAST) { }
public void defineToken(GrammarAST ID) { }
public void defineChannel(GrammarAST ID) { }
public void globalNamedAction(GrammarAST scope, GrammarAST ID, ActionAST action) { }
public void importGrammar(GrammarAST label, GrammarAST ID) { }

public void modeDef(GrammarAST m, GrammarAST ID) { }

public void discoverRules(GrammarAST rules) { }
public void finishRules(GrammarAST rule) { }
public void discoverRule(RuleAST rule, GrammarAST ID, List modifiers,
						 ActionAST arg, ActionAST returns, GrammarAST thrws,
						 GrammarAST options, ActionAST locals,
						 List actions,
						 GrammarAST block) { }
public void finishRule(RuleAST rule, GrammarAST ID, GrammarAST block) { }
public void discoverLexerRule(RuleAST rule, GrammarAST ID, List modifiers,
                              GrammarAST block) { }
public void finishLexerRule(RuleAST rule, GrammarAST ID, GrammarAST block) { }
public void ruleCatch(GrammarAST arg, ActionAST action) { }
public void finallyAction(ActionAST action) { }
public void discoverOuterAlt(AltAST alt) { }
public void finishOuterAlt(AltAST alt) { }
public void discoverAlt(AltAST alt) { }
public void finishAlt(AltAST alt) { }

public void ruleRef(GrammarAST ref, ActionAST arg) { }
public void tokenRef(TerminalAST ref) { }
public void elementOption(GrammarASTWithOptions t, GrammarAST ID, GrammarAST valueAST) { }
public void stringRef(TerminalAST ref) { }
public void wildcardRef(GrammarAST ref) { }
public void actionInAlt(ActionAST action) { }
public void sempredInAlt(PredAST pred) { }
public void label(GrammarAST op, GrammarAST ID, GrammarAST element) { }
public void lexerCallCommand(int outerAltNumber, GrammarAST ID, GrammarAST arg) { }
public void lexerCommand(int outerAltNumber, GrammarAST ID) { }

protected void enterGrammarSpec(GrammarAST tree) { }
protected void exitGrammarSpec(GrammarAST tree) { }

protected void enterPrequelConstructs(GrammarAST tree) { }
protected void exitPrequelConstructs(GrammarAST tree) { }

protected void enterPrequelConstruct(GrammarAST tree) { }
protected void exitPrequelConstruct(GrammarAST tree) { }

protected void enterOptionsSpec(GrammarAST tree) { }
protected void exitOptionsSpec(GrammarAST tree) { }

protected void enterOption(GrammarAST tree) { }
protected void exitOption(GrammarAST tree) { }

protected void enterOptionValue(GrammarAST tree) { }
protected void exitOptionValue(GrammarAST tree) { }

protected void enterDelegateGrammars(GrammarAST tree) { }
protected void exitDelegateGrammars(GrammarAST tree) { }

protected void enterDelegateGrammar(GrammarAST tree) { }
protected void exitDelegateGrammar(GrammarAST tree) { }

protected void enterTokensSpec(GrammarAST tree) { }
protected void exitTokensSpec(GrammarAST tree) { }

protected void enterTokenSpec(GrammarAST tree) { }
protected void exitTokenSpec(GrammarAST tree) { }

protected void enterChannelsSpec(GrammarAST tree) { }
protected void exitChannelsSpec(GrammarAST tree) { }

protected void enterChannelSpec(GrammarAST tree) { }
protected void exitChannelSpec(GrammarAST tree) { }

protected void enterAction(GrammarAST tree) { }
protected void exitAction(GrammarAST tree) { }

protected void enterRules(GrammarAST tree) { }
protected void exitRules(GrammarAST tree) { }

protected void enterMode(GrammarAST tree) { }
protected void exitMode(GrammarAST tree) { }

protected void enterLexerRule(GrammarAST tree) { }
protected void exitLexerRule(GrammarAST tree) { }

protected void enterRule(GrammarAST tree) { }
protected void exitRule(GrammarAST tree) { }

protected void enterExceptionGroup(GrammarAST tree) { }
protected void exitExceptionGroup(GrammarAST tree) { }

protected void enterExceptionHandler(GrammarAST tree) { }
protected void exitExceptionHandler(GrammarAST tree) { }

protected void enterFinallyClause(GrammarAST tree) { }
protected void exitFinallyClause(GrammarAST tree) { }

protected void enterLocals(GrammarAST tree) { }
protected void exitLocals(GrammarAST tree) { }

protected void enterRuleReturns(GrammarAST tree) { }
protected void exitRuleReturns(GrammarAST tree) { }

protected void enterThrowsSpec(GrammarAST tree) { }
protected void exitThrowsSpec(GrammarAST tree) { }

protected void enterRuleAction(GrammarAST tree) { }
protected void exitRuleAction(GrammarAST tree) { }

protected void enterRuleModifier(GrammarAST tree) { }
protected void exitRuleModifier(GrammarAST tree) { }

protected void enterLexerRuleBlock(GrammarAST tree) { }
protected void exitLexerRuleBlock(GrammarAST tree) { }

protected void enterRuleBlock(GrammarAST tree) { }
protected void exitRuleBlock(GrammarAST tree) { }

protected void enterLexerOuterAlternative(AltAST tree) { }
protected void exitLexerOuterAlternative(AltAST tree) { }

protected void enterOuterAlternative(AltAST tree) { }
protected void exitOuterAlternative(AltAST tree) { }

protected void enterLexerAlternative(GrammarAST tree) { }
protected void exitLexerAlternative(GrammarAST tree) { }

protected void enterLexerElements(GrammarAST tree) { }
protected void exitLexerElements(GrammarAST tree) { }

protected void enterLexerElement(GrammarAST tree) { }
protected void exitLexerElement(GrammarAST tree) { }

protected void enterLabeledLexerElement(GrammarAST tree) { }
protected void exitLabeledLexerElement(GrammarAST tree) { }

protected void enterLexerBlock(GrammarAST tree) { }
protected void exitLexerBlock(GrammarAST tree) { }

protected void enterLexerAtom(GrammarAST tree) { }
protected void exitLexerAtom(GrammarAST tree) { }

protected void enterActionElement(GrammarAST tree) { }
protected void exitActionElement(GrammarAST tree) { }

protected void enterAlternative(AltAST tree) { }
protected void exitAlternative(AltAST tree) { }

protected void enterLexerCommand(GrammarAST tree) { }
protected void exitLexerCommand(GrammarAST tree) { }

protected void enterLexerCommandExpr(GrammarAST tree) { }
protected void exitLexerCommandExpr(GrammarAST tree) { }

protected void enterElement(GrammarAST tree) { }
protected void exitElement(GrammarAST tree) { }

protected void enterAstOperand(GrammarAST tree) { }
protected void exitAstOperand(GrammarAST tree) { }

protected void enterLabeledElement(GrammarAST tree) { }
protected void exitLabeledElement(GrammarAST tree) { }

protected void enterSubrule(GrammarAST tree) { }
protected void exitSubrule(GrammarAST tree) { }

protected void enterLexerSubrule(GrammarAST tree) { }
protected void exitLexerSubrule(GrammarAST tree) { }

protected void enterBlockSuffix(GrammarAST tree) { }
protected void exitBlockSuffix(GrammarAST tree) { }

protected void enterEbnfSuffix(GrammarAST tree) { }
protected void exitEbnfSuffix(GrammarAST tree) { }

protected void enterAtom(GrammarAST tree) { }
protected void exitAtom(GrammarAST tree) { }

protected void enterBlockSet(GrammarAST tree) { }
protected void exitBlockSet(GrammarAST tree) { }

protected void enterSetElement(GrammarAST tree) { }
protected void exitSetElement(GrammarAST tree) { }

protected void enterBlock(GrammarAST tree) { }
protected void exitBlock(GrammarAST tree) { }

protected void enterRuleref(GrammarAST tree) { }
protected void exitRuleref(GrammarAST tree) { }

protected void enterRange(GrammarAST tree) { }
protected void exitRange(GrammarAST tree) { }

protected void enterTerminal(GrammarAST tree) { }
protected void exitTerminal(GrammarAST tree) { }

protected void enterElementOptions(GrammarAST tree) { }
protected void exitElementOptions(GrammarAST tree) { }

protected void enterElementOption(GrammarAST tree) { }
protected void exitElementOption(GrammarAST tree) { }

	@Override
	public void traceIn(String ruleName, int ruleIndex)  {
		System.err.println("enter "+ruleName+": "+input.LT(1));
	}

	@Override
	public void traceOut(String ruleName, int ruleIndex)  {
		System.err.println("exit "+ruleName+": "+input.LT(1));
	}
}

grammarSpec
@init {
	enterGrammarSpec($start);
}
@after {
	exitGrammarSpec($start);
}
    :   ^(	GRAMMAR ID {grammarName=$ID.text;}
    		{discoverGrammar((GrammarRootAST)$GRAMMAR, $ID);}
 		   	prequelConstructs
    		{finishPrequels($prequelConstructs.firstOne);}
 		   	rules mode*
    		{finishGrammar((GrammarRootAST)$GRAMMAR, $ID);}
 		 )
	;

prequelConstructs returns [GrammarAST firstOne=null]
@init {
	enterPrequelConstructs($start);
}
@after {
	exitPrequelConstructs($start);
}
	:	{$firstOne=$start;} prequelConstruct+
	|
	;

prequelConstruct
@init {
	enterPrequelConstructs($start);
}
@after {
	exitPrequelConstructs($start);
}
	:   optionsSpec
    |   delegateGrammars
    |   tokensSpec
    |   channelsSpec
    |   action
    ;

optionsSpec
@init {
	enterOptionsSpec($start);
}
@after {
	exitOptionsSpec($start);
}
	:	^(OPTIONS option*)
    ;

option
@init {
	enterOption($start);
	boolean rule = inContext("RULE ...");
	boolean block = inContext("BLOCK ...");
}
@after {
	exitOption($start);
}
    :   ^(a=ASSIGN ID v=optionValue)
    	{
    	if ( block ) blockOption($ID, $v.start); // most specific first
    	else if ( rule ) ruleOption($ID, $v.start);
    	else grammarOption($ID, $v.start);
    	}
    ;

optionValue returns [String v]
@init {
	enterOptionValue($start);
	$v = $start.token.getText();
}
@after {
	exitOptionValue($start);
}
    :   ID
    |   STRING_LITERAL
    |   INT
    ;

delegateGrammars
@init {
	enterDelegateGrammars($start);
}
@after {
	exitDelegateGrammars($start);
}
	:   ^(IMPORT delegateGrammar+)
	;

delegateGrammar
@init {
	enterDelegateGrammar($start);
}
@after {
	exitDelegateGrammar($start);
}
    :   ^(ASSIGN label=ID id=ID)	{importGrammar($label, $id);}
    |   id=ID						{importGrammar(null, $id);}
    ;

tokensSpec
@init {
	enterTokensSpec($start);
}
@after {
	exitTokensSpec($start);
}
	:   ^(TOKENS_SPEC tokenSpec+)
	;

tokenSpec
@init {
	enterTokenSpec($start);
}
@after {
	exitTokenSpec($start);
}
	:	ID					{defineToken($ID);}
	;

channelsSpec
@init {
	enterChannelsSpec($start);
}
@after {
	exitChannelsSpec($start);
}
	:   ^(CHANNELS channelSpec*)
	;

channelSpec
@init {
	enterChannelSpec($start);
}
@after {
	exitChannelSpec($start);
}
	:	ID					{defineChannel($ID);}
	;

action
@init {
	enterAction($start);
}
@after {
	exitAction($start);
}
	:	^(AT sc=ID? name=ID ACTION) {globalNamedAction($sc, $name, (ActionAST)$ACTION);}
	;

rules
@init {
	enterRules($start);
}
@after {
	exitRules($start);
}
    : ^(RULES {discoverRules($RULES);} (rule|lexerRule)* {finishRules($RULES);})
    ;

mode
@init {
	enterMode($start);
}
@after {
	exitMode($start);
}
	:	^( MODE ID {currentModeName=$ID.text; modeDef($MODE, $ID);} lexerRule* )
	;

lexerRule
@init {
	enterLexerRule($start);
	List mods = new ArrayList();
	currentOuterAltNumber=0;
}
@after {
	exitLexerRule($start);
}
	:	^(	RULE TOKEN_REF
			{currentRuleName=$TOKEN_REF.text; currentRuleAST=$RULE;}
			(^(RULEMODIFIERS m=FRAGMENT {mods.add($m);}))?
      		{discoverLexerRule((RuleAST)$RULE, $TOKEN_REF, mods, (GrammarAST)input.LT(1));}
      		lexerRuleBlock
      		{
      		finishLexerRule((RuleAST)$RULE, $TOKEN_REF, $lexerRuleBlock.start);
      		currentRuleName=null; currentRuleAST=null;
      		}
      	 )
	;

rule
@init {
	enterRule($start);
	List mods = new ArrayList();
	List actions = new ArrayList(); // track roots
	currentOuterAltNumber=0;
}
@after {
	exitRule($start);
}
	:   ^(	RULE RULE_REF {currentRuleName=$RULE_REF.text; currentRuleAST=$RULE;}
			(^(RULEMODIFIERS (m=ruleModifier{mods.add($m.start);})+))?
			ARG_ACTION?
      		ret=ruleReturns?
      		thr=throwsSpec?
      		loc=locals?
      		(	opts=optionsSpec
		    |   a=ruleAction {actions.add($a.start);}
		    )*
      		{discoverRule((RuleAST)$RULE, $RULE_REF, mods, (ActionAST)$ARG_ACTION,
      					  $ret.start!=null?(ActionAST)$ret.start.getChild(0):null,
      					  $thr.start, $opts.start,
      					  $loc.start!=null?(ActionAST)$loc.start.getChild(0):null,
      					  actions, (GrammarAST)input.LT(1));}
      		ruleBlock exceptionGroup
      		{finishRule((RuleAST)$RULE, $RULE_REF, $ruleBlock.start); currentRuleName=null; currentRuleAST=null;}
      	 )
    ;

exceptionGroup
@init {
	enterExceptionGroup($start);
}
@after {
	exitExceptionGroup($start);
}
    :	exceptionHandler* finallyClause?
    ;

exceptionHandler
@init {
	enterExceptionHandler($start);
}
@after {
	exitExceptionHandler($start);
}
	: ^(CATCH ARG_ACTION ACTION)	{ruleCatch($ARG_ACTION, (ActionAST)$ACTION);}
	;

finallyClause
@init {
	enterFinallyClause($start);
}
@after {
	exitFinallyClause($start);
}
	: ^(FINALLY ACTION)				{finallyAction((ActionAST)$ACTION);}
	;

locals
@init {
	enterLocals($start);
}
@after {
	exitLocals($start);
}
	:	^(LOCALS ARG_ACTION)
	;

ruleReturns
@init {
	enterRuleReturns($start);
}
@after {
	exitRuleReturns($start);
}
	: ^(RETURNS ARG_ACTION)
	;

throwsSpec
@init {
	enterThrowsSpec($start);
}
@after {
	exitThrowsSpec($start);
}
    : ^(THROWS ID+)
    ;

ruleAction
@init {
	enterRuleAction($start);
}
@after {
	exitRuleAction($start);
}
	:	^(AT ID ACTION)
	;

ruleModifier
@init {
	enterRuleModifier($start);
}
@after {
	exitRuleModifier($start);
}
    : PUBLIC
    | PRIVATE
    | PROTECTED
    | FRAGMENT
    ;

lexerRuleBlock
@init {
	enterLexerRuleBlock($start);
}
@after {
	exitLexerRuleBlock($start);
}
    :	^(	BLOCK
    		(	{
    			currentOuterAltRoot = (GrammarAST)input.LT(1);
				currentOuterAltNumber++;
				}
    			lexerOuterAlternative
    		)+
    	)
    ;

ruleBlock
@init {
	enterRuleBlock($start);
}
@after {
	exitRuleBlock($start);
}
    :	^(	BLOCK
    		(	{
    			currentOuterAltRoot = (GrammarAST)input.LT(1);
				currentOuterAltNumber++;
				}
    			outerAlternative
    		)+
    	)
    ;

lexerOuterAlternative
@init {
	enterLexerOuterAlternative((AltAST)$start);
	discoverOuterAlt((AltAST)$start);
}
@after {
	finishOuterAlt((AltAST)$start);
	exitLexerOuterAlternative((AltAST)$start);
}
	:	lexerAlternative
	;


outerAlternative
@init {
	enterOuterAlternative((AltAST)$start);
	discoverOuterAlt((AltAST)$start);
}
@after {
	finishOuterAlt((AltAST)$start);
	exitOuterAlternative((AltAST)$start);
}
	:	alternative
	;

lexerAlternative
@init {
	enterLexerAlternative($start);
}
@after {
	exitLexerAlternative($start);
}
	:	^(LEXER_ALT_ACTION lexerElements lexerCommand+)
    |   lexerElements
    ;

lexerElements
@init {
	enterLexerElements($start);
}
@after {
	exitLexerElements($start);
}
    :	^(ALT lexerElement+)
    ;

lexerElement
@init {
	enterLexerElement($start);
}
@after {
	exitLexerElement($start);
}
	:	labeledLexerElement
	|	lexerAtom
	|	lexerSubrule
	|   ACTION						{actionInAlt((ActionAST)$ACTION);}
	|   SEMPRED						{sempredInAlt((PredAST)$SEMPRED);}
	|   ^(ACTION elementOptions)	{actionInAlt((ActionAST)$ACTION);}
	|   ^(SEMPRED elementOptions)	{sempredInAlt((PredAST)$SEMPRED);}
	|	EPSILON
	;

labeledLexerElement
@init {
	enterLabeledLexerElement($start);
}
@after {
	exitLabeledLexerElement($start);
}
    :   ^((ASSIGN|PLUS_ASSIGN) ID (lexerAtom|block))
	;

lexerBlock
@init {
	enterLexerBlock($start);
}
@after {
	exitLexerBlock($start);
}
 	:	^(BLOCK optionsSpec? lexerAlternative+)
    ;

lexerAtom
@init {
	enterLexerAtom($start);
}
@after {
	exitLexerAtom($start);
}
    :   terminal
    |   ^(NOT blockSet)
    |   blockSet
    |   ^(WILDCARD elementOptions)
    |   WILDCARD
    |	LEXER_CHAR_SET
    |   range
    |   ruleref
    ;

actionElement
@init {
	enterActionElement($start);
}
@after {
	exitActionElement($start);
}
	:	ACTION
	|   ^(ACTION elementOptions)
	|   SEMPRED
	|   ^(SEMPRED elementOptions)
	;

alternative
@init {
	enterAlternative((AltAST)$start);
	discoverAlt((AltAST)$start);
}
@after {
	finishAlt((AltAST)$start);
	exitAlternative((AltAST)$start);
}
	:	^(ALT elementOptions? element+)
	|	^(ALT elementOptions? EPSILON)
    ;

lexerCommand
@init {
	enterLexerCommand($start);
}
@after {
	exitLexerCommand($start);
}
	:	^(LEXER_ACTION_CALL ID lexerCommandExpr)
        {lexerCallCommand(currentOuterAltNumber, $ID, $lexerCommandExpr.start);}
	|	ID
        {lexerCommand(currentOuterAltNumber, $ID);}
	;

lexerCommandExpr
@init {
	enterLexerCommandExpr($start);
}
@after {
	exitLexerCommandExpr($start);
}
	:	ID
	|	INT
	;

element
@init {
	enterElement($start);
}
@after {
	exitElement($start);
}
	:	labeledElement
	|	atom
	|	subrule
	|   ACTION						{actionInAlt((ActionAST)$ACTION);}
	|   SEMPRED						{sempredInAlt((PredAST)$SEMPRED);}
	|   ^(ACTION elementOptions)	{actionInAlt((ActionAST)$ACTION);}
	|   ^(SEMPRED elementOptions)	{sempredInAlt((PredAST)$SEMPRED);}
	|	range
	|	^(NOT blockSet)
	|	^(NOT block)
	;

astOperand
@init {
	enterAstOperand($start);
}
@after {
	exitAstOperand($start);
}
	:	atom
	|	^(NOT blockSet)
	|	^(NOT block)
	;

labeledElement
@init {
	enterLabeledElement($start);
}
@after {
	exitLabeledElement($start);
}
	:	^((ASSIGN|PLUS_ASSIGN) ID element) {label($start, $ID, $element.start);}
	;

subrule
@init {
	enterSubrule($start);
}
@after {
	exitSubrule($start);
}
	:	^(blockSuffix block)
	| 	block
    ;

lexerSubrule
@init {
	enterLexerSubrule($start);
}
@after {
	exitLexerSubrule($start);
}
	:	^(blockSuffix lexerBlock)
	| 	lexerBlock
    ;

blockSuffix
@init {
	enterBlockSuffix($start);
}
@after {
	exitBlockSuffix($start);
}
    : ebnfSuffix
    ;

ebnfSuffix
@init {
	enterEbnfSuffix($start);
}
@after {
	exitEbnfSuffix($start);
}
	:	OPTIONAL
  	|	CLOSURE
   	|	POSITIVE_CLOSURE
	;

atom
@init {
	enterAtom($start);
}
@after {
	exitAtom($start);
}
	:	^(DOT ID terminal)
	|	^(DOT ID ruleref)
    |	^(WILDCARD elementOptions)	{wildcardRef($WILDCARD);}
    |	WILDCARD					{wildcardRef($WILDCARD);}
    |   terminal
    |	blockSet
    |   ruleref
    ;

blockSet
@init {
	enterBlockSet($start);
}
@after {
	exitBlockSet($start);
}
	:	^(SET setElement+)
	;

setElement
@init {
	enterSetElement($start);
}
@after {
	exitSetElement($start);
}
	:	^(STRING_LITERAL elementOptions)    {stringRef((TerminalAST)$STRING_LITERAL);}
	|	^(TOKEN_REF elementOptions) 		{tokenRef((TerminalAST)$TOKEN_REF);}
	|	STRING_LITERAL                  	{stringRef((TerminalAST)$STRING_LITERAL);}
	|	TOKEN_REF		                    {tokenRef((TerminalAST)$TOKEN_REF);}
	|	^(RANGE a=STRING_LITERAL b=STRING_LITERAL)
		{
		stringRef((TerminalAST)$a);
		stringRef((TerminalAST)$b);
		}
        |       LEXER_CHAR_SET
	;

block
@init {
	enterBlock($start);
}
@after {
	exitBlock($start);
}
    :	^(BLOCK optionsSpec? ruleAction* ACTION? alternative+)
    ;

ruleref
@init {
	enterRuleref($start);
}
@after {
	exitRuleref($start);
}
    :	^(RULE_REF arg=ARG_ACTION? elementOptions?)
    	{
    	ruleRef($RULE_REF, (ActionAST)$ARG_ACTION);
    	if ( $arg!=null ) actionInAlt((ActionAST)$arg);
    	}
    ;

range
@init {
	enterRange($start);
}
@after {
	exitRange($start);
}
    : ^(RANGE STRING_LITERAL STRING_LITERAL)
    ;

terminal
@init {
	enterTerminal($start);
}
@after {
	exitTerminal($start);
}
    :  ^(STRING_LITERAL elementOptions)
    								{stringRef((TerminalAST)$STRING_LITERAL);}
    |	STRING_LITERAL				{stringRef((TerminalAST)$STRING_LITERAL);}
    |	^(TOKEN_REF elementOptions)	{tokenRef((TerminalAST)$TOKEN_REF);}
    |	TOKEN_REF	    			{tokenRef((TerminalAST)$TOKEN_REF);}
    ;

elementOptions
@init {
	enterElementOptions($start);
}
@after {
	exitElementOptions($start);
}
    :	^(ELEMENT_OPTIONS elementOption[(GrammarASTWithOptions)$start.getParent()]*)
    ;

elementOption[GrammarASTWithOptions t]
@init {
	enterElementOption($start);
}
@after {
	exitElementOption($start);
}
    :	ID								{elementOption(t, $ID, null);}
    |   ^(ASSIGN id=ID v=ID)			{elementOption(t, $id, $v);}
    |   ^(ASSIGN ID v=STRING_LITERAL)	{elementOption(t, $ID, $v);}
    |   ^(ASSIGN ID v=ACTION)			{elementOption(t, $ID, $v);}
    |   ^(ASSIGN ID v=INT)				{elementOption(t, $ID, $v);}
    ;