1 /*
2  * [The "BSD license"]
3  *  Copyright (c) 2010 Terence Parr
4  *  All rights reserved.
5  *
6  *  Redistribution and use in source and binary forms, with or without
7  *  modification, are permitted provided that the following conditions
8  *  are met:
9  *  1. Redistributions of source code must retain the above copyright
10  *      notice, this list of conditions and the following disclaimer.
11  *  2. Redistributions in binary form must reproduce the above copyright
12  *      notice, this list of conditions and the following disclaimer in the
13  *      documentation and/or other materials provided with the distribution.
14  *  3. The name of the author may not be used to endorse or promote products
15  *      derived from this software without specific prior written permission.
16  *
17  *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 package org.antlr.analysis;
29 
30 import org.antlr.tool.Rule;
31 
32 /** A transition used to reference another rule.  It tracks two targets
33  *  really: the actual transition target and the state following the
34  *  state that refers to the other rule.  Conversion of an NFA that
35  *  falls off the end of a rule will be able to figure out who invoked
36  *  that rule because of these special transitions.
37  */
38 public class RuleClosureTransition extends Transition {
39 	/** Ptr to the rule definition object for this rule ref */
40 	public Rule rule;
41 
42 	/** What node to begin computations following ref to rule */
43     public NFAState followState;
44 
RuleClosureTransition(Rule rule, NFAState ruleStart, NFAState followState)45     public RuleClosureTransition(Rule rule,
46 								 NFAState ruleStart,
47 								 NFAState followState)
48     {
49         super(Label.EPSILON, ruleStart);
50         this.rule = rule;
51         this.followState = followState;
52 	}
53 }
54 
55