SortField.cs
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- /*
- * 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.Search
- {
-
- /// <summary> Stores information about how to sort documents by terms in an individual
- /// field. Fields must be indexed in order to sort by them.
- ///
- /// <p>Created: Feb 11, 2004 1:25:29 PM
- ///
- /// </summary>
- /// <author> Tim Jones (Nacimiento Software)
- /// </author>
- /// <since> lucene 1.4
- /// </since>
- /// <version> $Id: SortField.java 150357 2004-05-24 22:51:42Z tjones $
- /// </version>
- /// <seealso cref="Sort">
- /// </seealso>
- [Serializable]
- public class SortField
- {
-
- /// <summary>Sort by document score (relevancy). Sort values are Float and higher
- /// values are at the front.
- /// </summary>
- public const int SCORE = 0;
-
- /// <summary>Sort by document number (index order). Sort values are Integer and lower
- /// values are at the front.
- /// </summary>
- public const int DOC = 1;
-
- /// <summary>Guess type of sort based on field contents. A regular expression is used
- /// to look at the first term indexed for the field and determine if it
- /// represents an integer number, a floating point number, or just arbitrary
- /// string characters.
- /// </summary>
- public const int AUTO = 2;
-
- /// <summary>Sort using term values as Strings. Sort values are String and lower
- /// values are at the front.
- /// </summary>
- public const int STRING = 3;
-
- /// <summary>Sort using term values as encoded Integers. Sort values are Integer and
- /// lower values are at the front.
- /// </summary>
- public const int INT = 4;
-
- /// <summary>Sort using term values as encoded Floats. Sort values are Float and
- /// lower values are at the front.
- /// </summary>
- public const int FLOAT = 5;
-
- /// <summary>Sort using a custom Comparator. Sort values are any Comparable and
- /// sorting is done according to natural order.
- /// </summary>
- public const int CUSTOM = 9;
-
- // IMPLEMENTATION NOTE: the FieldCache.STRING_INDEX is in the same "namespace"
- // as the above static int values. Any new values must not have the same value
- // as FieldCache.STRING_INDEX.
-
-
- /// <summary>Represents sorting by document score (relevancy). </summary>
- public static readonly SortField FIELD_SCORE = new SortField(null, SCORE);
-
- /// <summary>Represents sorting by document number (index order). </summary>
- public static readonly SortField FIELD_DOC = new SortField(null, DOC);
-
-
- private System.String field;
- private int type = AUTO; // defaults to determining type dynamically
- private System.Globalization.CultureInfo locale; // defaults to "natural order" (no Locale)
- internal bool reverse = false; // defaults to natural order
- private SortComparatorSource factory;
-
- /// <summary>Creates a sort by terms in the given field where the type of term value
- /// is determined dynamically ({@link #AUTO AUTO}).
- /// </summary>
- /// <param name="field">Name of field to sort by, cannot be <code>null</code>.
- /// </param>
- public SortField(System.String field)
- {
- this.field = String.Intern(field);
- }
-
- /// <summary>Creates a sort, possibly in reverse, by terms in the given field where
- /// the type of term value is determined dynamically ({@link #AUTO AUTO}).
- /// </summary>
- /// <param name="field">Name of field to sort by, cannot be <code>null</code>.
- /// </param>
- /// <param name="reverse">True if natural order should be reversed.
- /// </param>
- public SortField(System.String field, bool reverse)
- {
- this.field = String.Intern(field);
- this.reverse = reverse;
- }
-
- /// <summary>Creates a sort by terms in the given field with the type of term
- /// values explicitly given.
- /// </summary>
- /// <param name="field"> Name of field to sort by. Can be <code>null</code> if
- /// <code>type</code> is SCORE or DOC.
- /// </param>
- /// <param name="type"> Type of values in the terms.
- /// </param>
- public SortField(System.String field, int type)
- {
- this.field = (field != null)?String.Intern(field):field;
- this.type = type;
- }
-
- /// <summary>Creates a sort, possibly in reverse, by terms in the given field with the
- /// type of term values explicitly given.
- /// </summary>
- /// <param name="field"> Name of field to sort by. Can be <code>null</code> if
- /// <code>type</code> is SCORE or DOC.
- /// </param>
- /// <param name="type"> Type of values in the terms.
- /// </param>
- /// <param name="reverse">True if natural order should be reversed.
- /// </param>
- public SortField(System.String field, int type, bool reverse)
- {
- this.field = (field != null) ? String.Intern(field) : field;
- this.type = type;
- this.reverse = reverse;
- }
-
- /// <summary>Creates a sort by terms in the given field sorted
- /// according to the given locale.
- /// </summary>
- /// <param name="field"> Name of field to sort by, cannot be <code>null</code>.
- /// </param>
- /// <param name="locale">Locale of values in the field.
- /// </param>
- public SortField(System.String field, System.Globalization.CultureInfo locale)
- {
- this.field = String.Intern(field);
- this.type = STRING;
- this.locale = locale;
- }
-
- /// <summary>Creates a sort, possibly in reverse, by terms in the given field sorted
- /// according to the given locale.
- /// </summary>
- /// <param name="field"> Name of field to sort by, cannot be <code>null</code>.
- /// </param>
- /// <param name="locale">Locale of values in the field.
- /// </param>
- public SortField(System.String field, System.Globalization.CultureInfo locale, bool reverse)
- {
- this.field = String.Intern(field);
- this.type = STRING;
- this.locale = locale;
- this.reverse = reverse;
- }
-
- /// <summary>Creates a sort with a custom comparison function.</summary>
- /// <param name="field">Name of field to sort by; cannot be <code>null</code>.
- /// </param>
- /// <param name="comparator">Returns a comparator for sorting hits.
- /// </param>
- public SortField(System.String field, SortComparatorSource comparator)
- {
- this.field = (field != null)?String.Intern(field):field;
- this.type = CUSTOM;
- this.factory = comparator;
- }
-
- /// <summary>Creates a sort, possibly in reverse, with a custom comparison function.</summary>
- /// <param name="field">Name of field to sort by; cannot be <code>null</code>.
- /// </param>
- /// <param name="comparator">Returns a comparator for sorting hits.
- /// </param>
- /// <param name="reverse">True if natural order should be reversed.
- /// </param>
- public SortField(System.String field, SortComparatorSource comparator, bool reverse)
- {
- this.field = (field != null)?String.Intern(field):field;
- this.type = CUSTOM;
- this.reverse = reverse;
- this.factory = comparator;
- }
-
- /// <summary>Returns the name of the field. Could return <code>null</code>
- /// if the sort is by SCORE or DOC.
- /// </summary>
- /// <returns> Name of field, possibly <code>null</code>.
- /// </returns>
- public virtual System.String GetField()
- {
- return field;
- }
-
- /// <summary>Returns the type of contents in the field.</summary>
- /// <returns> One of the constants SCORE, DOC, AUTO, STRING, INT or FLOAT.
- /// </returns>
- public virtual int GetType()
- {
- return type;
- }
-
- /// <summary>Returns the Locale by which term values are interpreted.
- /// May return <code>null</code> if no Locale was specified.
- /// </summary>
- /// <returns> Locale, or <code>null</code>.
- /// </returns>
- public virtual System.Globalization.CultureInfo GetLocale()
- {
- return locale;
- }
-
- /// <summary>Returns whether the sort should be reversed.</summary>
- /// <returns> True if natural order should be reversed.
- /// </returns>
- public virtual bool GetReverse()
- {
- return reverse;
- }
-
- public virtual SortComparatorSource GetFactory()
- {
- return factory;
- }
-
- public override System.String ToString()
- {
- System.Text.StringBuilder buffer = new System.Text.StringBuilder();
- switch (type)
- {
-
- case SCORE: buffer.Append("<score>");
- break;
-
-
- case DOC: buffer.Append("<doc>");
- break;
-
-
- case CUSTOM:
- buffer.Append("<custom:"" + field + "": " + factory + ">");
- break;
-
-
- default: buffer.Append(""" + field + """);
- break;
-
- }
-
- if (locale != null)
- buffer.Append("(" + locale + ")");
- if (reverse)
- buffer.Append('!');
-
- return buffer.ToString();
- }
- }
- }