/*
* 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;
using TermPositionsLucene.Net.Index.TermPositions;
namespace Lucene.Net.Search{
sealed class SloppyPhraseScorer : PhraseScorer
{
private int slop;
internal SloppyPhraseScorer(Weight weight, TermPositions[] tps, int[] positions, Similarity similarity, int slop, byte[] norms) : base(weight, tps, positions, similarity, norms)
{
this.slop = slop;
}
protected internal override float PhraseFreq()
{
pq.Clear();
int end = 0;
for (PhrasePositions pp = first; pp != null; pp = pp.next)
{
pp.FirstPosition();
if (pp.position > end)
end = pp.position;
pq.Put(pp); // build pq from list
}
float freq = 0.0f;
bool done = false;
do
{
PhrasePositions pp = (PhrasePositions) pq.Pop();
int start = pp.position;
int next = ((PhrasePositions) pq.Top()).position;
for (int pos = start; pos <= next; pos = pp.position)
{
start = pos; // advance pp to min window
if (!pp.NextPosition())
{
done = true; // ran out of a term -- done
break;
}
}
int matchLength = end - start;
if (matchLength <= slop)
freq += GetSimilarity().SloppyFreq(matchLength); // score match
if (pp.position > end)
end = pp.position;
pq.Put(pp); // restore pq
}
while (!done);
return freq;
}
}
}
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