VDLtQuotedString.java

/*
 * This file or a portion of this file is licensed under the terms of
 * the Globus Toolkit Public License, found in file GTPL, or at
 * http://www.globus.org/toolkit/download/license.html. This notice must
 * appear in redistributions of this file, with or without modification.
 *
 * Redistributions of this Software, with or without modification, must
 * reproduce the GTPL in: (1) the Software, or (2) the Documentation or
 * some other similar material which is provided with the Software (if
 * any).
 *
 * Copyright 1999-2004 University of Chicago and The University of
 * Southern California. All rights reserved.
 */
package org.griphyn.vdl.parser;

/**
 * Class to pass the content from a quoted string from scanner to parser.
 * This class is module-local on purpose.
 *
 * @author Jens-S. Vöckler
 * @version $Revision$
 *
 */
class VDLtQuotedString
  implements VDLtToken
{
  /**
   * The content of the string to be passed.
   */
  private String m_value;
  
  /**
   * Contructs a new string value to pass.
   * @param value is the content of the string.
   */
  public VDLtQuotedString( String value )
  {
    this.m_value = value == null ? null : new String(value);
  }

  /**
   * Obtains the current, unmodified content of the string. This
   * means that quote characters inside the string will remain
   * as-is.
   * @return the content of the quoted string. 
   */
  public String getValue()
  {
    return this.m_value;
  }

  /**
   * Turns the content of a string into a quoted version of itself.
   * The quote and backslash character are quoted by prepending a
   * backslash in front of them. Single quotes (apostrophe) are not
   * touched. 
   * @param unquoted is the raw string that may require quoting.
   * @return null if the input was null, or the quoted string.
   */
  public static String getQuotedValue( String unquoted )
  {
    if ( unquoted == null ) return null;

    StringBuffer result = new StringBuffer( unquoted.length() );
    for ( int i=0; i<unquoted.length(); ++i ) {
      char ch = unquoted.charAt(i);
      if ( ch == '\\' || ch == '\"' ) result.append('\\');
      result.append(ch);
    }

    return result.toString();
  }
}