bundles/org.eclipse.osgi/core/adaptor/org/eclipse/osgi/framework/util/Tokenizer.java

/*******************************************************************************
 * Copyright (c) 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.osgi.framework.util;

/**
 * Simple tokenizer class. Used to parse data.
 */
public class Tokenizer
{
    protected char value[];
    protected int max;
    protected int cursor;

    public Tokenizer(String value)
    {
        this.value = value.toCharArray();
        max = this.value.length;
        cursor = 0;
    }

    private void skipWhiteSpace()
    {
        char[] val = value;
        int cur = cursor;

        for ( ;cur < max; cur++)
        {
            char c = val[cur];
            if ((c == ' ') || (c == '\t') || (c == '\n') || (c == '\r'))
            {
                continue;
            }
            break;
        }
        cursor = cur;
    }

    public String getToken(String terminals)
    {
        skipWhiteSpace();
        char[] val = value;
        int cur = cursor;

        int begin = cur;
        for ( ;cur < max; cur++)
        {
            char c = val[cur];
            if ((terminals.indexOf(c) != -1))
            {
                break;
            }
        }
        cursor = cur;
        int count = cur-begin;
        if (count > 0)
        {
            skipWhiteSpace();
            while (count>0 && (val[begin+count-1] == ' ' || val[begin+count-1] == '\t'))
            	count--;
            return(new String(val, begin, count));
        }
        return(null);
    }

    public String getString(String terminals)
    {
        skipWhiteSpace();
        char[] val = value;
        int cur = cursor;

        if (cur < max)
        {
            if (val[cur] == '\"')  /* if a quoted string */
            {
                cur++;               /* skip quote */
                char c = '\0';
                int begin = cur;
                for ( ;cur < max; cur++)
                {
                    c = val[cur];
                    if (c == '\"')
                    {
                        break;
                    }
                }
                int count = cur-begin;
                if (c == '\"')
                {
                    cur++;
                }
                cursor = cur;
                if (count > 0)
                {
                    skipWhiteSpace();
                    return(new String(val, begin, count));
                }
            }
            else    /* not a quoted string; same as token */
            {
                int begin = cur;
                for ( ;cur < max; cur++)
                {
                    char c = val[cur];
                    if (c=='\"') {
                        // but there could be a quoted string in the middle of the string
                        cur = cur+skipQuotedString(val,cur);
                    } else if ((terminals.indexOf(c) != -1)) {
                        break;
                    }
                }
                cursor = cur;
                int count = cur-begin;
                if (count > 0)
                {
                    skipWhiteSpace();
                    while (count>0 && (val[begin+count-1] == ' ' || val[begin+count-1] == '\t'))
                    	count--;
                    return(new String(val, begin, count));
                }
            }
        }
        return(null);
    }
    
    private int skipQuotedString(char[] val, int cur) {
        cur++;               /* skip quote */
        char c = '\0';
        int begin = cur;
        for ( ;cur < max; cur++)
        {
            c = val[cur];
            if (c == '\"')
            {
                break;
            }
        }
        int count = cur-begin;
        if (c == '\"')
        {
            cur++;
        }
        cursor = cur;
        if (count > 0)
        {
            skipWhiteSpace();
        }
        return count;
    }

    public char getChar()
    {
        int cur = cursor;
        if (cur < max)
        {
            cursor = cur+1;
            return(value[cur]);
        }
        return('\0');   /* end of value */
    }
    
    public boolean hasMoreTokens() {
        if (cursor<max) {
            return true;
        }
        return false;
    }
}