PrefixAndSuffixAwareTokenFilter.cs

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/*
 * 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.
 */

namespace Lucene.Net.Analysis.Miscellaneous
{
    public class PrefixAndSuffixAwareTokenFilter : TokenStream
    {
        private readonly PrefixAwareTokenFilter _suffix;

        public PrefixAndSuffixAwareTokenFilter(TokenStream prefix, TokenStream input, TokenStream suffix) : base(suffix)
        {
            _suffix =
                new InjectablePrefixAwareTokenFilter(
                    new InjectablePrefixAwareTokenFilter(prefix, input)
                        {
                            UpdateAction = UpdateInputToken
                        },
                    suffix)
                    {
                        UpdateAction = UpdateSuffixToken
                    };
        }

        public Token UpdateInputToken(Token inputToken, Token lastPrefixToken)
        {
            inputToken.StartOffset = lastPrefixToken.EndOffset + inputToken.StartOffset;
            inputToken.EndOffset = lastPrefixToken.EndOffset + inputToken.EndOffset;
            return inputToken;
        }

        public Token UpdateSuffixToken(Token suffixToken, Token lastInputToken)
        {
            suffixToken.StartOffset = lastInputToken.EndOffset + suffixToken.StartOffset;
            suffixToken.EndOffset = lastInputToken.EndOffset + suffixToken.EndOffset;
            return suffixToken;
        }


        public override sealed bool IncrementToken()
        {
            return _suffix.IncrementToken();
        }

        public override void Reset()
        {
            _suffix.Reset();
        }

        protected override void Dispose(bool disposing)
        {
            _suffix.Dispose();
        }
    }
}