using Lucene.Net.Analysis.TokenAttributes;
using System.IO;

namespace Lucene.Net.Analysis.Standard
{
    /*
     * Licensed to the Apache Software Foundation (ASF) under one or more
     * contributor license agreements.  See the NOTICE file distributed with
     * this work for additional information regarding copyright ownership.
     * The ASF licenses this file to You under the Apache License, Version 2.0
     * (the "License"); you may not use this file except in compliance with
     * the License.  You may obtain a copy of the License at
     *
     *     http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */

    /// <summary>
    /// Internal interface for supporting versioned grammars.
    /// @lucene.internal 
    /// </summary>
    public interface IStandardTokenizerInterface
    {
        /// <summary>
        /// Copies the matched text into the <see cref="ICharTermAttribute"/>
        /// </summary>
        void GetText(ICharTermAttribute t);

        /// <summary>
        /// Returns the current position.
        /// </summary>
        int YyChar { get; }

        /// <summary>
        /// Resets the scanner to read from a new input stream.
        /// Does not close the old reader.
        /// <para/>
        /// All internal variables are reset, the old input stream 
        /// <b>cannot</b> be reused (internal buffer is discarded and lost).
        /// Lexical state is set to <c>YYINITIAL</c>.
        /// </summary>
        /// <param name="reader">   the new input stream  </param>
        void YyReset(TextReader reader);

        /// <summary>
        /// Returns the length of the matched text region.
        /// </summary>
        int YyLength { get; }

        /// <summary>
        /// Resumes scanning until the next regular expression is matched,
        /// the end of input is encountered or an I/O-Error occurs.
        /// </summary>
        /// <returns>      the next token, <see cref="StandardTokenizerInterface.YYEOF"/> on end of stream </returns>
        /// <exception cref="IOException">  if any I/O-Error occurs </exception>
        int GetNextToken();
    }

    public static class StandardTokenizerInterface
    {
        /// <summary>
        /// This character denotes the end of file </summary>
        public const int YYEOF = -1;
    }
}