beagled/Lucene.Net/Index/Term.cs

   1 /*
   2  * Copyright 2004 The Apache Software Foundation
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 using System;
  17 namespace Lucene.Net.Index
  18 {
  19     /// <summary>A Term represents a word from text.  This is the unit of search.  It is
  20     /// composed of two elements, the text of the word, as a string, and the name of
  21     /// the Field that the text occured in, an interned string.
  22     /// Note that terms may represent more than words from text fields, but also
  23     /// things like dates, email addresses, urls, etc.
  24     /// </summary>
  25     [Serializable]
  26         public sealed class Term : System.IComparable
  27         {
  28                 internal System.String field;
  29                 public /*internal*/ System.String text;
  30
  31                 /// <summary>Constructs a Term with the given Field and text. </summary>
  32                 public Term(System.String fld, System.String txt) : this(fld, txt, true)
  33                 {
  34                 }
  35                 internal Term(System.String fld, System.String txt, bool intern)
  36                 {
  37                         field = intern ? String.Intern(fld) : fld; // Field names are interned
  38                         text = txt; // unless already known to be
  39                 }
  40
  41                 /// <summary>Returns the Field of this term, an interned string.   The Field indicates
  42                 /// the part of a document which this term came from.
  43                 /// </summary>
  44                 public System.String Field()
  45                 {
  46                         return field;
  47                 }
  48
  49                 /// <summary>Returns the text of this term.  In the case of words, this is simply the
  50                 /// text of the word.  In the case of dates and other types, this is an
  51                 /// encoding of the object as a string.
  52                 /// </summary>
  53                 public System.String Text()
  54                 {
  55                         return text;
  56                 }
  57
  58                 /// <summary>Compares two terms, returning true iff they have the same
  59                 /// Field and text.
  60                 /// </summary>
  61                 public  override bool Equals(System.Object o)
  62                 {
  63                         if (o == null)
  64                                 return false;
  65                         Term other = (Term) o;
  66                         return (System.Object) field == (System.Object) other.field && text.Equals(other.text);
  67                 }
  68
  69                 /// <summary>Combines the hashCode() of the Field and the text. </summary>
  70                 public override int GetHashCode()
  71                 {
  72                         return field.GetHashCode() + text.GetHashCode();
  73                 }
  74
  75                 public int CompareTo(System.Object other)
  76                 {
  77                         return CompareTo((Term) other);
  78                 }
  79
  80                 /// <summary>Compares two terms, returning an integer which is less than zero iff this
  81                 /// term belongs after the argument, equal zero iff this term is equal to the
  82                 /// argument, and greater than zero iff this term belongs after the argument.
  83                 /// The ordering of terms is first by Field, then by text.
  84                 /// </summary>
  85                 public int CompareTo(Term other)
  86                 {
  87                         if ((System.Object) field == (System.Object) other.field)
  88                         // fields are interned
  89                                 return String.CompareOrdinal(text, other.text);
  90                         else
  91                                 return String.CompareOrdinal(field, other.field);
  92                 }
  93
  94                 /// <summary>Resets the Field and text of a Term. </summary>
  95                 internal void  Set(System.String fld, System.String txt)
  96                 {
  97                         field = String.Intern(fld); // FIXED(?) trow@novell.com on May 24, 2005
  98                         text = txt;
  99                 }
 100
 101                 public override System.String ToString()
 102                 {
 103                         return field + ":" + text;
 104                 }
 105
 106                 private void  ReadObject(System.IO.BinaryReader in_Renamed)
 107                 {
 108                         // This function is private and is never been called, so this may not be a port issue. // {{Aroush}}
 109                         // in_Renamed.defaultReadObject(); // {{Aroush}} >> 'java.io.ObjectInputStream.defaultReadObject()'
 110                         field = String.Intern(field);
 111                 }
 112
 113                 // {{Aroush: Or is this what we want (vs. the above)?!!
 114                 private void GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
 115                 {
 116                         info.AddValue("field", field);
 117                         info.AddValue("text", text);
 118                 }
 119                 // Aroush}}
 120         }
 121 }