xref: /external/antlr/antlr-3.4/runtime/CSharp3/Sources/Antlr3.Runtime/CharStreamState.cs

/*
 * [The "BSD licence"]
 * Copyright (c) 2005-2008 Terence Parr
 * All rights reserved.
 *
 * Conversion to C#:
 * Copyright (c) 2008 Sam Harwell, Pixel Mine, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

namespace Antlr.Runtime
{

    /** <summary>
     *  When walking ahead with cyclic DFA or for syntactic predicates,
     *  we need to record the state of the input stream (char index,
     *  line, etc...) so that we can rewind the state after scanning ahead.
     *  </summary>
     *
     *  <remarks>This is the complete state of a stream.</remarks>
     */
    [System.Serializable]
    public class CharStreamState
    {
        /** <summary>Index into the char stream of next lookahead char</summary> */
        public int p;

        /** <summary>What line number is the scanner at before processing buffer[p]?</summary> */
        public int line;

        /** <summary>What char position 0..n-1 in line is scanner before processing buffer[p]?</summary> */
        public int charPositionInLine;
    }
}