/*
* Copyright 2010 NCHOVY
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.krakenapps.bnf;
import java.text.ParseException;
public class Literal implements Rule {
private String token;
private boolean isCaseInsensitive;
public Literal(String token) {
this.token = token;
}
public Literal(String token, boolean isCaseInsensitive) {
this.token = token.toLowerCase();
this.isCaseInsensitive = isCaseInsensitive;
}
@Override
public Result eval(String text, int position, ParserContext ctx) throws ParseException {
position = StringUtil.skipSpaces(text, position);
if (isCaseInsensitive) {
if (text.length() < position + token.length())
throw new ParseException("literal eval() failed", position);
for (int i = 0; i < token.length(); i++) {
char c = text.charAt(position + i);
if (c >= 'A' && c <= 'Z')
c += 32;
if (c != token.charAt(i))
throw new ParseException("literal eval() failed", position + i);
}
return new Result(new Binding(this, token), position + token.length());
}
if (text.startsWith(token, position)) {
return new Result(new Binding(this, token), position + token.length());
}
throw new ParseException("literal eval() failed", position);
}
@Override
public String toString() {
return "literal '" + token + "'";
}
}