1 | /* |
2 | * Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0, |
3 | * and the EPL 1.0 (http://h2database.com/html/license.html). |
4 | * Initial Developer: H2 Group |
5 | */ |
6 | package org.h2.bnf; |
7 | |
8 | import java.util.HashMap; |
9 | |
10 | /** |
11 | * Represents an optional BNF rule. |
12 | */ |
13 | public class RuleOptional implements Rule { |
14 | private final Rule rule; |
15 | private boolean mapSet; |
16 | |
17 | public RuleOptional(Rule rule) { |
18 | this.rule = rule; |
19 | } |
20 | |
21 | @Override |
22 | public void accept(BnfVisitor visitor) { |
23 | visitor.visitRuleOptional(rule); |
24 | } |
25 | |
26 | @Override |
27 | public void setLinks(HashMap<String, RuleHead> ruleMap) { |
28 | if (!mapSet) { |
29 | rule.setLinks(ruleMap); |
30 | mapSet = true; |
31 | } |
32 | } |
33 | @Override |
34 | public boolean autoComplete(Sentence sentence) { |
35 | sentence.stopIfRequired(); |
36 | rule.autoComplete(sentence); |
37 | return true; |
38 | } |
39 | |
40 | } |