/*
* Copyright 2008 Ayman Al-Sairafi ayman.alsairafi@gmail.com
*
* 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 jsyntaxpane;
import java.io.Reader;
/**
* Lexers must implement these methods. These are used in the Tokenizer
*
* A Lexer should be tied to one document.
*
* @author Ayman Al-Sairafi
*/
public interface Lexer {
/**
* This will be called to reset the the lexer, generally whenever a
* document is changed
* @param reader
*/
public void yyreset(Reader reader);
/**
* This is called to return the next Token from the Input Reader
* @return next token, or null if no more tokens.
* @throws java.io.IOException
*/
public Token yylex() throws java.io.IOException;
/**
* Returns the character at position <tt>pos</tt> from the
* matched text.
*
* It is equivalent to yytext().charAt(pos), but faster
*
* @param pos the position of the character to fetch.
* A value from 0 to yylength()-1.
*
* @return the character at position pos
*/
public char yycharat(int pos);
/**
* Returns the length of the matched text region.
*/
public int yylength();
/**
* Returns the text matched by the current regular expression.
*/
public String yytext();
}