AbstractParser.java

package org.codehaus.mojo.natives.parser;


/*
 *
 * Copyright 2001-2004 The Ant-Contrib project
 *
 *  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.
 */

import java.io.IOException;
import java.io.Reader;



/**
 * An abstract base class for simple parsers
 *
 * @author Curt Arnold
 */
public abstract class AbstractParser {


    protected AbstractParser() 
    {
    }
    
    protected abstract void addFilename(String filename);
    
    public abstract AbstractParserState getNewLineState();
    
    protected void parse(Reader reader) 
        throws IOException 
    {
        char[] buf = new char[4096];
        AbstractParserState newLineState = getNewLineState();
        AbstractParserState state = newLineState;
        int charsRead = -1;
        
        do 
        {
            charsRead = reader.read(buf, 0, buf.length);
            if (state == null) 
            {
                for (int i = 0; i < charsRead; i++) 
                {
                    if (buf[i] == '\n') 
                    {
                        state = newLineState;
                        break;
                    }
                }
            }
            
            if (state != null) 
            {
                for (int i = 0; i < charsRead; i++) 
                {
                    state = state.consume(buf[i]);
                    //
                    //  didn't match a production, skip to a new line
                    //
                    if (state == null) 
                    {
                        for (; i < charsRead; i++) 
                        {
                            if (buf[i] == '\n') 
                            {
                                state = newLineState;
                                break;
                            }
                        }
                    }
                }
            }
            
        } while (charsRead >= 0);
    }
}