C# IndexReader.Terms方法代码示例

		/// <summary> Creates a new <c>WildcardTermEnum</c>.
		/// <p/>
		/// After calling the constructor the enumeration is already pointing to the first 
		/// valid term if such a term exists.
		/// </summary>
		public WildcardTermEnum(IndexReader reader, Term term):base()
		{
			searchTerm = term;
			field = searchTerm.Field;
			System.String searchTermText = searchTerm.Text;
			
			int sidx = searchTermText.IndexOf((System.Char) WILDCARD_STRING);
			int cidx = searchTermText.IndexOf((System.Char) WILDCARD_CHAR);
			int idx = sidx;
			if (idx == - 1)
			{
				idx = cidx;
			}
			else if (cidx >= 0)
			{
				idx = System.Math.Min(idx, cidx);
			}
			pre = idx != - 1?searchTerm.Text.Substring(0, (idx) - (0)):"";
			
			preLen = pre.Length;
			text = searchTermText.Substring(preLen);
			SetEnum(reader.Terms(new Term(searchTerm.Field, pre)));
		}

 protected internal override System.Object CreateValue(IndexReader reader, Entry entryKey)
 {
     System.String field = StringHelper.Intern(entryKey.field);
     int[] retArray = new int[reader.MaxDoc];
     System.String[] mterms = new System.String[reader.MaxDoc + 1];
     TermDocs termDocs = reader.TermDocs();
     TermEnum termEnum = reader.Terms(new Term(field));
     int t = 0; // current term number
     
     // an entry for documents that have no terms in this field
     // should a document with no terms be at top or bottom?
     // this puts them at the top - if it is changed, FieldDocSortedHitQueue
     // needs to change as well.
     mterms[t++] = null;
     
     try
     {
         do 
         {
             Term term = termEnum.Term;
             if (term == null || term.Field != field || t >= mterms.Length) break;
             
             // store term text
             mterms[t] = term.Text;
             
             termDocs.Seek(termEnum);
             while (termDocs.Next())
             {
                 retArray[termDocs.Doc] = t;
             }
             
             t++;
         }
         while (termEnum.Next());
     }
     finally
     {
         termDocs.Close();
         termEnum.Close();
     }
     
     if (t == 0)
     {
         // if there are no terms, make the term array
         // have a single null entry
         mterms = new System.String[1];
     }
     else if (t < mterms.Length)
     {
         // if there are less terms than documents,
         // trim off the dead array space
         System.String[] terms = new System.String[t];
         Array.Copy(mterms, 0, terms, 0, t);
         mterms = terms;
     }
     
     StringIndex value_Renamed = new StringIndex(retArray, mterms);
     return value_Renamed;
 }

		/// <summary> Enumerates all terms greater/equal than <c>lowerTerm</c>
		/// but less/equal than <c>upperTerm</c>. 
		/// 
		/// If an endpoint is null, it is said to be "open". Either or both 
		/// endpoints may be open.  Open endpoints may not be exclusive 
		/// (you can't select all but the first or last term without 
		/// explicitly specifying the term to exclude.)
		/// 
		/// </summary>
		/// <param name="reader">
		/// </param>
		/// <param name="field">An interned field that holds both lower and upper terms.
		/// </param>
		/// <param name="lowerTermText">The term text at the lower end of the range
		/// </param>
		/// <param name="upperTermText">The term text at the upper end of the range
		/// </param>
		/// <param name="includeLower">If true, the <c>lowerTerm</c> is included in the range.
		/// </param>
		/// <param name="includeUpper">If true, the <c>upperTerm</c> is included in the range.
		/// </param>
		/// <param name="collator">The collator to use to collate index Terms, to determine their
		/// membership in the range bounded by <c>lowerTerm</c> and
		/// <c>upperTerm</c>.
		/// 
		/// </param>
		/// <throws>  IOException </throws>
		public TermRangeTermEnum(IndexReader reader, System.String field, System.String lowerTermText, System.String upperTermText, bool includeLower, bool includeUpper, System.Globalization.CompareInfo collator)
		{
			this.collator = collator;
			this.upperTermText = upperTermText;
			this.lowerTermText = lowerTermText;
			this.includeLower = includeLower;
			this.includeUpper = includeUpper;
			this.field = StringHelper.Intern(field);
			
			// do a little bit of normalization...
			// open ended range queries should always be inclusive.
			if (this.lowerTermText == null)
			{
				this.lowerTermText = "";
				this.includeLower = true;
			}
			
			if (this.upperTermText == null)
			{
				this.includeUpper = true;
			}
			
			System.String startTermText = collator == null?this.lowerTermText:"";
			SetEnum(reader.Terms(new Term(this.field, startTermText)));
		}

		public PrefixTermEnum(IndexReader reader, Term prefix)
		{
			this.prefix = prefix;
			
			SetEnum(reader.Terms(new Term(prefix.Field, prefix.Text)));
		}

		/// <summary> Constructor for enumeration of all terms from specified <c>reader</c> which share a prefix of
		/// length <c>prefixLength</c> with <c>term</c> and which have a fuzzy similarity &gt;
		/// <c>minSimilarity</c>.
		/// <p/>
		/// After calling the constructor the enumeration is already pointing to the first 
		/// valid term if such a term exists. 
		/// 
		/// </summary>
		/// <param name="reader">Delivers terms.
		/// </param>
		/// <param name="term">Pattern term.
		/// </param>
		/// <param name="minSimilarity">Minimum required similarity for terms from the reader. Default value is 0.5f.
		/// </param>
		/// <param name="prefixLength">Length of required common prefix. Default value is 0.
		/// </param>
		/// <throws>  IOException </throws>
		public FuzzyTermEnum(IndexReader reader, Term term, float minSimilarity, int prefixLength):base()
		{
			
			if (minSimilarity >= 1.0f)
				throw new System.ArgumentException("minimumSimilarity cannot be greater than or equal to 1");
			else if (minSimilarity < 0.0f)
				throw new System.ArgumentException("minimumSimilarity cannot be less than 0");
			if (prefixLength < 0)
				throw new System.ArgumentException("prefixLength cannot be less than 0");
			
			this.minimumSimilarity = minSimilarity;
			this.scale_factor = 1.0f / (1.0f - minimumSimilarity);
			this.searchTerm = term;
			this.field = searchTerm.Field;
			
			//The prefix could be longer than the word.
			//It's kind of silly though.  It means we must match the entire word.
			int fullSearchTermLength = searchTerm.Text.Length;
			int realPrefixLength = prefixLength > fullSearchTermLength?fullSearchTermLength:prefixLength;
			
			this.text = searchTerm.Text.Substring(realPrefixLength);
			this.prefix = searchTerm.Text.Substring(0, (realPrefixLength) - (0));

		    this.p = new int[this.text.Length + 1];
            this.d = new int[this.text.Length + 1];
			
			SetEnum(reader.Terms(new Term(searchTerm.Field, prefix)));
		}

 /// <summary>
 /// Creates a new <c>SingleTermEnum</c>.
 /// <p/>
 /// After calling the constructor the enumeration is already pointing to the term,
 ///  if it exists.
 /// </summary>
 public SingleTermEnum(IndexReader reader, Term singleTerm)
 {
     this.singleTerm = singleTerm;
     SetEnum(reader.Terms(singleTerm));
 }