| /* |
| * [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.analysis; |
| |
| /** A generic transition between any two state machine states. It defines |
| * some special labels that indicate things like epsilon transitions and |
| * that the label is actually a set of labels or a semantic predicate. |
| * This is a one way link. It emanates from a state (usually via a list of |
| * transitions) and has a label/target pair. I have abstracted the notion |
| * of a Label to handle the various kinds of things it can be. |
| */ |
| public class Transition implements Comparable { |
| /** What label must be consumed to transition to target */ |
| public Label label; |
| |
| /** The target of this transition */ |
| public State target; |
| |
| public Transition(Label label, State target) { |
| this.label = label; |
| this.target = target; |
| } |
| |
| public Transition(int label, State target) { |
| this.label = new Label(label); |
| this.target = target; |
| } |
| |
| public boolean isEpsilon() { |
| return label.isEpsilon(); |
| } |
| |
| public boolean isAction() { |
| return label.isAction(); |
| } |
| |
| public boolean isSemanticPredicate() { |
| return label.isSemanticPredicate(); |
| } |
| |
| public int hashCode() { |
| return label.hashCode() + target.stateNumber; |
| } |
| |
| public boolean equals(Object o) { |
| Transition other = (Transition)o; |
| return this.label.equals(other.label) && |
| this.target.equals(other.target); |
| } |
| |
| public int compareTo(Object o) { |
| Transition other = (Transition)o; |
| return this.label.compareTo(other.label); |
| } |
| |
| public String toString() { |
| return label+"->"+target.stateNumber; |
| } |
| } |