/*
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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.
*/
using System;
namespace Lucene.Net.Index{
/// <summary>Abstract class for enumerating terms.
/// <p>Term enumerations are always ordered by Term.compareTo(). Each term in
/// the enumeration is greater than all that precede it.
/// </summary>
public abstract class TermEnum
{
/// <summary>Increments the enumeration to the next element. True if one exists.</summary>
public abstract bool Next();
/// <summary>Returns the current Term in the enumeration.</summary>
public abstract Term Term();
/// <summary>Returns the docFreq of the current Term in the enumeration.</summary>
public abstract int DocFreq();
/// <summary>Closes the enumeration to further activity, freeing resources. </summary>
public abstract void Close();
// Term Vector support
/// <summary>Skips terms to the first beyond the current whose value is
/// greater or equal to <i>target</i>. <p>Returns true iff there is such
/// an entry. <p>Behaves as if written: <pre>
/// public boolean skipTo(Term target) {
/// do {
/// if (!next())
/// return false;
/// } while (target > term());
/// return true;
/// }
/// </pre>
/// Some implementations are considerably more efficient than that.
/// </summary>
public virtual bool SkipTo(Term target)
{
do
{
if (!Next())
return false;
}
while (target.CompareTo(Term()) > 0);
return true;
}
}
}
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