/*
 * Word.java
 *
 * Copyright (c) 1997 Cornell University.
 * Copyright (c) 1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and
 * redistribution of this file, and for a DISCLAIMER OF ALL
 * WARRANTIES.
 *
 * RCS: @(#) $Id: Word.java,v 1.1.1.1 1998/10/14 21:09:21 cvsadmin Exp $
 *
 */

package tcl.lang;

import java.util.*;

/**
 * This class is used to store a word during the parsing of Tcl commands.
 */
class Word {
    StringBuffer sbuf;
    TclObject obj;


    /**
     * Number of objects that have been concatenated into this word.
     */
    int objCount;

    Word() {
	sbuf = null;
	obj = null;
	objCount = 0;
    }

    void append(TclObject o) {
	/*
	 * The object inside a word must be preserved. Otherwise code like
	 * the following will fail (prints out 2020 instead of 1020):
	 *
	 *	set a 10
	 *	puts $a[set a 20]
	 */

	if (sbuf != null) {
	    sbuf.append(o.toString());
	} else if (obj != null) {
	    sbuf = new StringBuffer(obj.toString());
	    obj.release();
	    obj = null;
	    sbuf.append(o.toString());
	} else {
	    obj = o;
	    obj.preserve();
	}

	objCount ++;
    }

    void append(char c) {
	if (sbuf != null) {
	    sbuf.append(c);
	} else if (obj != null) {
	    sbuf = new StringBuffer(obj.toString());
	    obj.release();
	    obj = null;
	    sbuf.append(c);
	} else {
	    sbuf = new StringBuffer();
	    sbuf.append(c);
	}

	objCount ++;
    }

    TclObject getTclObject() {
	if (sbuf != null) {
	    obj = TclString.newInstance(sbuf.toString());
	    obj.preserve();
	    return obj;
	} else if (obj != null) {
	    return obj;
	} else {
	    obj = TclString.newInstance("");
	    obj.preserve();
	    return obj;
	}
    }
}