Token.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.commons.csv;

import static org.apache.commons.csv.Token.Type.*;

/**
 * Token is an internal token representation.
 * <p/>
 * It is used as contract between the lexer and the parser.
 */
class Token {

    /** length of the initial token (content-)buffer */
    private static final int INITIAL_TOKEN_LENGTH = 50;
    
    enum Type {
        /** Token has no valid content, i.e. is in its initialized state. */
        INVALID,
        
        /** Token with content, at beginning or in the middle of a line. */
        TOKEN,
        
        /** Token (which can have content) when end of file is reached. */
        EOF,
        
        /** Token with content when end of a line is reached. */
        EORECORD,
        
        /** Token is a comment line */
        COMMENT
    }
    
    /** Token type */
    Token.Type type = INVALID;
    
    /** The content buffer. */
    StringBuilder content = new StringBuilder(INITIAL_TOKEN_LENGTH);
    
    /** Token ready flag: indicates a valid token with content (ready for the parser). */
    boolean isReady;

    Token reset() {
        content.setLength(0);
        type = INVALID;
        isReady = false;
        return this;
    }

    // Provide toString method for IDE debugging
    @Override
    public String toString() {
        return type.name()+" ["+content.toString()+"]";
    }
}