org.h2.bnf.RuleElement Maven / Gradle / Ivy
/*
* Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.bnf;
import java.util.HashMap;
import org.h2.util.StringUtils;
/**
* A single terminal rule in a BNF object.
*/
public class RuleElement implements Rule {
private final boolean keyword;
private final String name;
private Rule link;
private final int type;
public RuleElement(String name, String topic) {
this.name = name;
this.keyword = name.length() == 1 ||
name.equals(StringUtils.toUpperEnglish(name));
topic = StringUtils.toLowerEnglish(topic);
this.type = topic.startsWith("function") ?
Sentence.FUNCTION : Sentence.KEYWORD;
}
@Override
public void accept(BnfVisitor visitor) {
visitor.visitRuleElement(keyword, name, link);
}
@Override
public void setLinks(HashMap ruleMap) {
if (link != null) {
link.setLinks(ruleMap);
}
if (keyword) {
return;
}
String test = Bnf.getRuleMapKey(name);
for (int i = 0; i < test.length(); i++) {
String t = test.substring(i);
RuleHead r = ruleMap.get(t);
if (r != null) {
link = r.getRule();
return;
}
}
throw new AssertionError("Unknown " + name + "/" + test);
}
@Override
public boolean autoComplete(Sentence sentence) {
sentence.stopIfRequired();
if (keyword) {
String query = sentence.getQuery();
String q = query.trim();
String up = sentence.getQueryUpper().trim();
if (up.startsWith(name)) {
query = query.substring(name.length());
while (!"_".equals(name) && Bnf.startWithSpace(query)) {
query = query.substring(1);
}
sentence.setQuery(query);
return true;
} else if (q.length() == 0 || name.startsWith(up)) {
if (q.length() < name.length()) {
sentence.add(name, name.substring(q.length()), type);
}
}
return false;
}
return link.autoComplete(sentence);
}
}