NFA.java revision 324c4644fee44b9898524c09511bd33c3f12e2df 
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 */
28package org.antlr.analysis;
29
30import org.antlr.tool.Grammar;
31import org.antlr.tool.NFAFactory;
32
33/** An NFA (collection of NFAStates) constructed from a grammar.  This
34 *  NFA is one big machine for entire grammar.  Decision points are recorded
35 *  by the Grammar object so we can, for example, convert to DFA or simulate
36 *  the NFA (interpret a decision).
37 */
38public class NFA {
39    public static final int INVALID_ALT_NUMBER = -1;
40
41    /** This NFA represents which grammar? */
42    public Grammar grammar;
43
44	/** Which factory created this NFA? */
45    protected NFAFactory factory = null;
46
47	public boolean complete;
48
49	public NFA(Grammar g) {
50        this.grammar = g;
51    }
52
53	public int getNewNFAStateNumber() {
54		return grammar.composite.getNewNFAStateNumber();
55	}
56
57	public void addState(NFAState state) {
58		grammar.composite.addState(state);
59    }
60
61    public NFAState getState(int s) {
62		return grammar.composite.getState(s);
63    }
64
65    public NFAFactory getFactory() {
66        return factory;
67    }
68
69    public void setFactory(NFAFactory factory) {
70        this.factory = factory;
71    }
72}
73
74