' 
' * Element.cs 
' * 
' * This library is free software; you can redistribute it and/or 
' * modify it under the terms of the GNU Lesser General Public License 
' * as published by the Free Software Foundation; either version 2.1 
' * of the License, or (at your option) any later version. 
' * 
' * This library is distributed in the hope that it will be useful, 
' * but WITHOUT ANY WARRANTY; without even the implied warranty of 
' * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
' * Lesser General Public License for more details. 
' * 
' * You should have received a copy of the GNU Lesser General Public 
' * License along with this library; if not, write to the Free 
' * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
' * MA 02111-1307, USA. 
' * 
' * Copyright (c) 2003-2005 Per Cederberg. All rights reserved. 
' 

' Converted to VB.NET	[Eugene Ciloci; Nov 24, 2007]

Imports System 
Imports System.IO 

Imports Ciloci.Flee.PerCederberg.Grammatica.Runtime

Namespace PerCederberg.Grammatica.Runtime.RE 
    
    '* 
' * A regular expression element. This is the common base class for 
' * all regular expression elements, i.e. the parts of the regular 
' * expression. 
' * 
' * @author Per Cederberg, <per at percederberg dot net> 
' * @version 1.0 
' 
    
    Friend MustInherit Class Element 
        Implements ICloneable 
        
        '* 
' * Creates a copy of this element. The copy will be an 
' * instance of the same class matching the same strings. 
' * Copies of elements are necessary to allow elements to cache 
' * intermediate results while matching strings without 
' * interfering with other threads. 
' * 
' * @return a copy of this element 
' 
        
		Public MustOverride Function Clone() As Object Implements ICloneable.Clone
        
        '* 
' * Returns the length of a matching string starting at the 
' * specified position. The number of matches to skip can also 
' * be specified, but numbers higher than zero (0) cause a 
' * failed match for any element that doesn't attempt to 
' * combine other elements. 
' * 
' * @param m the matcher being used 
' * @param input the input character stream to match 
' * @param start the starting position 
' * @param skip the number of matches to skip 
' * 
' * @return the length of the matching string, or 
' * -1 if no match was found 
' * 
' * @throws IOException if an I/O error occurred 
' 
        
        Public MustOverride Function Match(ByVal m As Matcher, ByVal input As LookAheadReader, ByVal start As Integer, ByVal skip As Integer) As Integer 
        
        '* 
' * Prints this element to the specified output stream. 
' * 
' * @param output the output stream to use 
' * @param indent the current indentation 
' 
        
        Public MustOverride Sub PrintTo(ByVal output As TextWriter, ByVal indent As String) 
    End Class 
End Namespace