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The ANTLR 4 grammar compiler.
There is a newer version: 4.9.0
/*
 * [The "BSD license"]
 *  Copyright (c) 2012 Terence Parr
 *  Copyright (c) 2012 Sam Harwell
 *  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.v4.codegen.model;

import org.antlr.v4.codegen.CodeGenerator;
import org.antlr.v4.codegen.OutputModelFactory;
import org.antlr.v4.runtime.atn.PlusBlockStartState;
import org.antlr.v4.runtime.misc.IntervalSet;
import org.antlr.v4.tool.Grammar;
import org.antlr.v4.tool.ast.GrammarAST;

import java.util.List;

/** */
public class LL1PlusBlock extends LL1Loop {
	/** Token names for each alt 0..n-1 */
	public List altLook;

	public String loopLabel;
	public String loopCounterVar;
	public String[] exitLook;

	@ModelElement public ThrowNoViableAlt error;

	public LL1PlusBlock(OutputModelFactory factory, GrammarAST plusRoot, List alts) {
		super(factory, plusRoot, alts);

		PlusBlockStartState blkStart = (PlusBlockStartState)plusRoot.atnState;

		stateNumber = blkStart.loopBackState.stateNumber;
		blockStartStateNumber = blkStart.stateNumber;

		this.decision = blkStart.decision;
		Grammar g = factory.getGrammar();
		CodeGenerator gen = factory.getGenerator();
		/** Lookahead for each alt 1..n */
		IntervalSet[] altLookSets = g.decisionLOOK.get(decision);
		altLook = getAltLookaheadAsStringLists(altLookSets);
		IntervalSet all = IntervalSet.or(altLookSets);

		this.error = getThrowNoViableAlt(factory, plusRoot, all);

		loopExpr = addCodeForLoopLookaheadTempVar(all);

		loopLabel = gen.getTarget().getLoopLabel(plusRoot);
		loopCounterVar = gen.getTarget().getLoopCounter(plusRoot);

		IntervalSet exitLookSet = altLookSets[altLookSets.length-1];
		this.exitLook = gen.getTarget().getTokenTypesAsTargetLabels(g,
															   exitLookSet.toArray());
	}
}