src/Lucene.Net/Search/PhraseQuery.cs - lucenenet - Git at Google

 /*
  * 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.
  */

 using System;

 using Term = Lucene.Net.Index.Term;
 using TermPositions = Lucene.Net.Index.TermPositions;
 using IndexReader = Lucene.Net.Index.IndexReader;
 using ToStringUtils = Lucene.Net.Util.ToStringUtils;

 namespace Lucene.Net.Search
 {

 	/// <summary>A Query that matches documents containing a particular sequence of terms.
 	/// A PhraseQuery is built by QueryParser for input like <code>"new york"</code>.
 	///
 	/// <p>This query may be combined with other terms or queries with a {@link BooleanQuery}.
 	/// </summary>
 	[Serializable]
 	public class PhraseQuery : Query
 	{
 		private System.String field;
 		private System.Collections.ArrayList terms = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(10));
 		private System.Collections.ArrayList positions = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(10));
 		private int slop = 0;

 		/// <summary>Constructs an empty phrase query. </summary>
 		public PhraseQuery()
 		{
 		}

 		/// <summary>Sets the number of other words permitted between words in query phrase.
 		/// If zero, then this is an exact phrase search.  For larger values this works
 		/// like a <code>WITHIN</code> or <code>NEAR</code> operator.
 		/// <p>The slop is in fact an edit-distance, where the units correspond to
 		/// moves of terms in the query phrase out of position.  For example, to switch
 		/// the order of two words requires two moves (the first move places the words
 		/// atop one another), so to permit re-orderings of phrases, the slop must be
 		/// at least two.
 		/// <p>More exact matches are scored higher than sloppier matches, thus search
 		/// results are sorted by exactness.
 		/// <p>The slop is zero by default, requiring exact matches.
 		/// </summary>
 		public virtual void  SetSlop(int s)
 		{
 			slop = s;
 		}
 		/// <summary>Returns the slop.  See setSlop(). </summary>
 		public virtual int GetSlop()
 		{
 			return slop;
 		}

 		/// <summary> Adds a term to the end of the query phrase.
 		/// The relative position of the term is the one immediately after the last term added.
 		/// </summary>
 		public virtual void  Add(Term term)
 		{
 			int position = 0;
 			if (positions.Count > 0)
 				position = ((System.Int32) positions[positions.Count - 1]) + 1;

 			Add(term, position);
 		}

 		/// <summary> Adds a term to the end of the query phrase.
 		/// The relative position of the term within the phrase is specified explicitly.
 		/// This allows e.g. phrases with more than one term at the same position
 		/// or phrases with gaps (e.g. in connection with stopwords).
 		///
 		/// </summary>
 		/// <param name="">term
 		/// </param>
 		/// <param name="">position
 		/// </param>
 		public virtual void  Add(Term term, int position)
 		{
 			if (terms.Count == 0)
 				field = term.Field();
 			else if (term.Field() != field)
 			{
 				throw new System.ArgumentException("All phrase terms must be in the same field: " + term);
 			}

 			terms.Add(term);
 			positions.Add((System.Int32) position);
 		}

 		/// <summary>Returns the set of terms in this phrase. </summary>
 		public virtual Term[] GetTerms()
 		{
 			return (Term[]) terms.ToArray(typeof(Term));
 		}

 		/// <summary> Returns the relative positions of terms in this phrase.</summary>
 		public virtual int[] GetPositions()
 		{
 			int[] result = new int[positions.Count];
 			for (int i = 0; i < positions.Count; i++)
 				result[i] = ((System.Int32) positions[i]);
 			return result;
 		}

 		[Serializable]
 		private class PhraseWeight : Weight
 		{
 			private void  InitBlock(PhraseQuery enclosingInstance)
 			{
 				this.enclosingInstance = enclosingInstance;
 			}
 			private PhraseQuery enclosingInstance;
 			public PhraseQuery Enclosing_Instance
 			{
 				get
 				{
 					return enclosingInstance;
 				}

 			}
 			private Similarity similarity;
 			private float value_Renamed;
 			private float idf;
 			private float queryNorm;
 			private float queryWeight;

 			public PhraseWeight(PhraseQuery enclosingInstance, Searcher searcher)
 			{
 				InitBlock(enclosingInstance);
 				this.similarity = Enclosing_Instance.GetSimilarity(searcher);

 				idf = similarity.Idf(Enclosing_Instance.terms, searcher);
 			}

 			public override System.String ToString()
 			{
 				return "weight(" + Enclosing_Instance + ")";
 			}

 			public virtual Query GetQuery()
 			{
 				return Enclosing_Instance;
 			}
 			public virtual float GetValue()
 			{
 				return value_Renamed;
 			}

 			public virtual float SumOfSquaredWeights()
 			{
 				queryWeight = idf * Enclosing_Instance.GetBoost(); // compute query weight
 				return queryWeight * queryWeight; // square it
 			}

 			public virtual void  Normalize(float queryNorm)
 			{
 				this.queryNorm = queryNorm;
 				queryWeight *= queryNorm; // normalize query weight
 				value_Renamed = queryWeight * idf; // idf for document
 			}

 			public virtual Scorer Scorer(IndexReader reader)
 			{
 				if (Enclosing_Instance.terms.Count == 0)
 				// optimize zero-term case
 					return null;

 				TermPositions[] tps = new TermPositions[Enclosing_Instance.terms.Count];
 				for (int i = 0; i < Enclosing_Instance.terms.Count; i++)
 				{
 					TermPositions p = reader.TermPositions((Term) Enclosing_Instance.terms[i]);
 					if (p == null)
 						return null;
 					tps[i] = p;
 				}

 				if (Enclosing_Instance.slop == 0)
 				// optimize exact case
 					return new ExactPhraseScorer(this, tps, Enclosing_Instance.GetPositions(), similarity, reader.Norms(Enclosing_Instance.field));
 				else
 					return new SloppyPhraseScorer(this, tps, Enclosing_Instance.GetPositions(), similarity, Enclosing_Instance.slop, reader.Norms(Enclosing_Instance.field));
 			}

 			public virtual Explanation Explain(IndexReader reader, int doc)
 			{

 				Explanation result = new Explanation();
 				result.SetDescription("weight(" + GetQuery() + " in " + doc + "), product of:");

 				System.Text.StringBuilder docFreqs = new System.Text.StringBuilder();
 				System.Text.StringBuilder query = new System.Text.StringBuilder();
 				query.Append('\"');
 				for (int i = 0; i < Enclosing_Instance.terms.Count; i++)
 				{
 					if (i != 0)
 					{
 						docFreqs.Append(" ");
 						query.Append(" ");
 					}

 					Term term = (Term) Enclosing_Instance.terms[i];

 					docFreqs.Append(term.Text());
 					docFreqs.Append("=");
 					docFreqs.Append(reader.DocFreq(term));

 					query.Append(term.Text());
 				}
 				query.Append('\"');

 				Explanation idfExpl = new Explanation(idf, "idf(" + Enclosing_Instance.field + ": " + docFreqs + ")");

 				// explain query weight
 				Explanation queryExpl = new Explanation();
 				queryExpl.SetDescription("queryWeight(" + GetQuery() + "), product of:");

 				Explanation boostExpl = new Explanation(Enclosing_Instance.GetBoost(), "boost");
 				if (Enclosing_Instance.GetBoost() != 1.0f)
 					queryExpl.AddDetail(boostExpl);
 				queryExpl.AddDetail(idfExpl);

 				Explanation queryNormExpl = new Explanation(queryNorm, "queryNorm");
 				queryExpl.AddDetail(queryNormExpl);

 				queryExpl.SetValue(boostExpl.GetValue() * idfExpl.GetValue() * queryNormExpl.GetValue());

 				result.AddDetail(queryExpl);

 				// explain field weight
 				Explanation fieldExpl = new Explanation();
 				fieldExpl.SetDescription("fieldWeight(" + Enclosing_Instance.field + ":" + query + " in " + doc + "), product of:");

 				Explanation tfExpl = Scorer(reader).Explain(doc);
 				fieldExpl.AddDetail(tfExpl);
 				fieldExpl.AddDetail(idfExpl);

 				Explanation fieldNormExpl = new Explanation();
 				byte[] fieldNorms = reader.Norms(Enclosing_Instance.field);
 				float fieldNorm = fieldNorms != null ? Similarity.DecodeNorm(fieldNorms[doc]) : 0.0f;
 				fieldNormExpl.SetValue(fieldNorm);
 				fieldNormExpl.SetDescription("fieldNorm(field=" + Enclosing_Instance.field + ", doc=" + doc + ")");
 				fieldExpl.AddDetail(fieldNormExpl);

 				fieldExpl.SetValue(tfExpl.GetValue() * idfExpl.GetValue() * fieldNormExpl.GetValue());

 				result.AddDetail(fieldExpl);

 				// combine them
 				result.SetValue(queryExpl.GetValue() * fieldExpl.GetValue());

 				if (queryExpl.GetValue() == 1.0f)
 					return fieldExpl;

 				return result;
 			}
 		}

 		protected internal override Weight CreateWeight(Searcher searcher)
 		{
 			if (terms.Count == 1)
 			{
 				// optimize one-term case
 				Term term = (Term) terms[0];
 				Query termQuery = new TermQuery(term);
 				termQuery.SetBoost(GetBoost());
 				return termQuery.CreateWeight(searcher);
 			}
 			return new PhraseWeight(this, searcher);
 		}

 		/// <seealso cref="Lucene.Net.Search.Query#ExtractTerms(java.util.Set)">
 		/// </seealso>
 		public override void  ExtractTerms(System.Collections.Hashtable queryTerms)
 		{
             foreach (Term term in terms)
             {
                 if (queryTerms.Contains(term) == false)
                 {
                     queryTerms.Add(term, term);
                 }
             }
         }

 		/// <summary>Prints a user-readable version of this query. </summary>
 		public override System.String ToString(System.String f)
 		{
 			System.Text.StringBuilder buffer = new System.Text.StringBuilder();
 			if (!field.Equals(f))
 			{
 				buffer.Append(field);
 				buffer.Append(":");
 			}

 			buffer.Append("\"");
 			for (int i = 0; i < terms.Count; i++)
 			{
 				buffer.Append(((Term) terms[i]).Text());
 				if (i != terms.Count - 1)
 					buffer.Append(" ");
 			}
 			buffer.Append("\"");

 			if (slop != 0)
 			{
 				buffer.Append("~");
 				buffer.Append(slop);
 			}

 			buffer.Append(ToStringUtils.Boost(GetBoost()));

 			return buffer.ToString();
 		}

         /// <summary>Returns true iff <code>o</code> is equal to this. </summary>
         public  override bool Equals(System.Object o)
         {
             if (!(o is PhraseQuery))
                 return false;
             PhraseQuery other = (PhraseQuery) o;
             return (this.GetBoost() == other.GetBoost()) &&
                 (this.slop == other.slop) &&
                 this.terms.Equals(other.terms) &&
                 this.positions.Equals(other.positions);
         }

         /// <summary>Returns a hash code value for this object.</summary>
         public override int GetHashCode()
         {
             return BitConverter.ToInt32(BitConverter.GetBytes(GetBoost()), 0) ^ slop ^ terms.GetHashCode() ^ positions.GetHashCode();
         }
     }
 }
	/*
	* 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.
	*/

	using System;

	using Term = Lucene.Net.Index.Term;
	using TermPositions = Lucene.Net.Index.TermPositions;
	using IndexReader = Lucene.Net.Index.IndexReader;
	using ToStringUtils = Lucene.Net.Util.ToStringUtils;

	namespace Lucene.Net.Search
	{

	/// <summary>A Query that matches documents containing a particular sequence of terms.
	/// A PhraseQuery is built by QueryParser for input like <code>"new york"</code>.
	///
	/// <p>This query may be combined with other terms or queries with a {@link BooleanQuery}.
	/// </summary>
	[Serializable]
	public class PhraseQuery : Query
	{
	private System.String field;
	private System.Collections.ArrayList terms = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(10));
	private System.Collections.ArrayList positions = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(10));
	private int slop = 0;

	/// <summary>Constructs an empty phrase query. </summary>
	public PhraseQuery()
	{
	}

	/// <summary>Sets the number of other words permitted between words in query phrase.
	/// If zero, then this is an exact phrase search. For larger values this works
	/// like a <code>WITHIN</code> or <code>NEAR</code> operator.
	/// <p>The slop is in fact an edit-distance, where the units correspond to
	/// moves of terms in the query phrase out of position. For example, to switch
	/// the order of two words requires two moves (the first move places the words
	/// atop one another), so to permit re-orderings of phrases, the slop must be
	/// at least two.
	/// <p>More exact matches are scored higher than sloppier matches, thus search
	/// results are sorted by exactness.
	/// <p>The slop is zero by default, requiring exact matches.
	/// </summary>
	public virtual void SetSlop(int s)
	{
	slop = s;
	}
	/// <summary>Returns the slop. See setSlop(). </summary>
	public virtual int GetSlop()
	{
	return slop;
	}

	/// <summary> Adds a term to the end of the query phrase.
	/// The relative position of the term is the one immediately after the last term added.
	/// </summary>
	public virtual void Add(Term term)
	{
	int position = 0;
	if (positions.Count > 0)
	position = ((System.Int32) positions[positions.Count - 1]) + 1;

	Add(term, position);
	}

	/// <summary> Adds a term to the end of the query phrase.
	/// The relative position of the term within the phrase is specified explicitly.
	/// This allows e.g. phrases with more than one term at the same position
	/// or phrases with gaps (e.g. in connection with stopwords).
	///
	/// </summary>
	/// <param name="">term
	/// </param>
	/// <param name="">position
	/// </param>
	public virtual void Add(Term term, int position)
	{
	if (terms.Count == 0)
	field = term.Field();
	else if (term.Field() != field)
	{
	throw new System.ArgumentException("All phrase terms must be in the same field: " + term);
	}

	terms.Add(term);
	positions.Add((System.Int32) position);
	}

	/// <summary>Returns the set of terms in this phrase. </summary>
	public virtual Term[] GetTerms()
	{
	return (Term[]) terms.ToArray(typeof(Term));
	}

	/// <summary> Returns the relative positions of terms in this phrase.</summary>
	public virtual int[] GetPositions()
	{
	int[] result = new int[positions.Count];
	for (int i = 0; i < positions.Count; i++)
	result[i] = ((System.Int32) positions[i]);
	return result;
	}

	[Serializable]
	private class PhraseWeight : Weight
	{
	private void InitBlock(PhraseQuery enclosingInstance)
	{
	this.enclosingInstance = enclosingInstance;
	}
	private PhraseQuery enclosingInstance;
	public PhraseQuery Enclosing_Instance
	{
	get
	{
	return enclosingInstance;
	}

	}
	private Similarity similarity;
	private float value_Renamed;
	private float idf;
	private float queryNorm;
	private float queryWeight;

	public PhraseWeight(PhraseQuery enclosingInstance, Searcher searcher)
	{
	InitBlock(enclosingInstance);
	this.similarity = Enclosing_Instance.GetSimilarity(searcher);

	idf = similarity.Idf(Enclosing_Instance.terms, searcher);
	}

	public override System.String ToString()
	{
	return "weight(" + Enclosing_Instance + ")";
	}

	public virtual Query GetQuery()
	{
	return Enclosing_Instance;
	}
	public virtual float GetValue()
	{
	return value_Renamed;
	}

	public virtual float SumOfSquaredWeights()
	{
	queryWeight = idf * Enclosing_Instance.GetBoost(); // compute query weight
	return queryWeight * queryWeight; // square it
	}

	public virtual void Normalize(float queryNorm)
	{
	this.queryNorm = queryNorm;
	queryWeight *= queryNorm; // normalize query weight
	value_Renamed = queryWeight * idf; // idf for document
	}

	public virtual Scorer Scorer(IndexReader reader)
	{
	if (Enclosing_Instance.terms.Count == 0)
	// optimize zero-term case
	return null;

	TermPositions[] tps = new TermPositions[Enclosing_Instance.terms.Count];
	for (int i = 0; i < Enclosing_Instance.terms.Count; i++)
	{
	TermPositions p = reader.TermPositions((Term) Enclosing_Instance.terms[i]);
	if (p == null)
	return null;
	tps[i] = p;
	}

	if (Enclosing_Instance.slop == 0)
	// optimize exact case
	return new ExactPhraseScorer(this, tps, Enclosing_Instance.GetPositions(), similarity, reader.Norms(Enclosing_Instance.field));
	else
	return new SloppyPhraseScorer(this, tps, Enclosing_Instance.GetPositions(), similarity, Enclosing_Instance.slop, reader.Norms(Enclosing_Instance.field));
	}

	public virtual Explanation Explain(IndexReader reader, int doc)
	{

	Explanation result = new Explanation();
	result.SetDescription("weight(" + GetQuery() + " in " + doc + "), product of:");

	System.Text.StringBuilder docFreqs = new System.Text.StringBuilder();
	System.Text.StringBuilder query = new System.Text.StringBuilder();
	query.Append('\"');
	for (int i = 0; i < Enclosing_Instance.terms.Count; i++)
	{
	if (i != 0)
	{
	docFreqs.Append(" ");
	query.Append(" ");
	}

	Term term = (Term) Enclosing_Instance.terms[i];

	docFreqs.Append(term.Text());
	docFreqs.Append("=");
	docFreqs.Append(reader.DocFreq(term));

	query.Append(term.Text());
	}
	query.Append('\"');

	Explanation idfExpl = new Explanation(idf, "idf(" + Enclosing_Instance.field + ": " + docFreqs + ")");

	// explain query weight
	Explanation queryExpl = new Explanation();
	queryExpl.SetDescription("queryWeight(" + GetQuery() + "), product of:");

	Explanation boostExpl = new Explanation(Enclosing_Instance.GetBoost(), "boost");
	if (Enclosing_Instance.GetBoost() != 1.0f)
	queryExpl.AddDetail(boostExpl);
	queryExpl.AddDetail(idfExpl);

	Explanation queryNormExpl = new Explanation(queryNorm, "queryNorm");
	queryExpl.AddDetail(queryNormExpl);

	queryExpl.SetValue(boostExpl.GetValue() * idfExpl.GetValue() * queryNormExpl.GetValue());

	result.AddDetail(queryExpl);

	// explain field weight
	Explanation fieldExpl = new Explanation();
	fieldExpl.SetDescription("fieldWeight(" + Enclosing_Instance.field + ":" + query + " in " + doc + "), product of:");

	Explanation tfExpl = Scorer(reader).Explain(doc);
	fieldExpl.AddDetail(tfExpl);
	fieldExpl.AddDetail(idfExpl);

	Explanation fieldNormExpl = new Explanation();
	byte[] fieldNorms = reader.Norms(Enclosing_Instance.field);
	float fieldNorm = fieldNorms != null ? Similarity.DecodeNorm(fieldNorms[doc]) : 0.0f;
	fieldNormExpl.SetValue(fieldNorm);
	fieldNormExpl.SetDescription("fieldNorm(field=" + Enclosing_Instance.field + ", doc=" + doc + ")");
	fieldExpl.AddDetail(fieldNormExpl);

	fieldExpl.SetValue(tfExpl.GetValue() * idfExpl.GetValue() * fieldNormExpl.GetValue());

	result.AddDetail(fieldExpl);

	// combine them
	result.SetValue(queryExpl.GetValue() * fieldExpl.GetValue());

	if (queryExpl.GetValue() == 1.0f)
	return fieldExpl;

	return result;
	}
	}

	protected internal override Weight CreateWeight(Searcher searcher)
	{
	if (terms.Count == 1)
	{
	// optimize one-term case
	Term term = (Term) terms[0];
	Query termQuery = new TermQuery(term);
	termQuery.SetBoost(GetBoost());
	return termQuery.CreateWeight(searcher);
	}
	return new PhraseWeight(this, searcher);
	}

	/// <seealso cref="Lucene.Net.Search.Query#ExtractTerms(java.util.Set)">
	/// </seealso>
	public override void ExtractTerms(System.Collections.Hashtable queryTerms)
	{
	foreach (Term term in terms)
	{
	if (queryTerms.Contains(term) == false)
	{
	queryTerms.Add(term, term);
	}
	}
	}

	/// <summary>Prints a user-readable version of this query. </summary>
	public override System.String ToString(System.String f)
	{
	System.Text.StringBuilder buffer = new System.Text.StringBuilder();
	if (!field.Equals(f))
	{
	buffer.Append(field);
	buffer.Append(":");
	}

	buffer.Append("\"");
	for (int i = 0; i < terms.Count; i++)
	{
	buffer.Append(((Term) terms[i]).Text());
	if (i != terms.Count - 1)
	buffer.Append(" ");
	}
	buffer.Append("\"");

	if (slop != 0)
	{
	buffer.Append("~");
	buffer.Append(slop);
	}

	buffer.Append(ToStringUtils.Boost(GetBoost()));

	return buffer.ToString();
	}

	/// <summary>Returns true iff <code>o</code> is equal to this. </summary>
	public override bool Equals(System.Object o)
	{
	if (!(o is PhraseQuery))
	return false;
	PhraseQuery other = (PhraseQuery) o;
	return (this.GetBoost() == other.GetBoost()) &&
	(this.slop == other.slop) &&
	this.terms.Equals(other.terms) &&
	this.positions.Equals(other.positions);
	}

	/// <summary>Returns a hash code value for this object.</summary>
	public override int GetHashCode()
	{
	return BitConverter.ToInt32(BitConverter.GetBytes(GetBoost()), 0) ^ slop ^ terms.GetHashCode() ^ positions.GetHashCode();
	}
	}
	}