Class CharacterUtils

CharacterUtils provides a unified interface to Character-related operations to implement backwards compatible character operations based on a LuceneVersion instance.

@lucene.internal

Inheritance
System.Object
CharacterUtils
Inherited Members
System.Object.ToString()
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
Assembly: Lucene.Net.Analysis.Common.dll
Syntax
[Serializable]
public abstract class CharacterUtils

Methods

Name Description
CodePointAt(ICharSequence, Int32)
CodePointAt(Char[], Int32, Int32)

Returns the code point at the given index of the char array where only elements with index less than the limit are used. Depending on the LuceneVersion passed to GetInstance(LuceneVersion) this method mimics the behavior of Character.CodePointAt(char[], int) as it would have been available on a Java 1.4 JVM or on a later virtual machine version.
CodePointAt(String, Int32)

Returns the code point at the given index of the ICharSequence. Depending on the LuceneVersion passed to GetInstance(LuceneVersion) this method mimics the behavior of Character.CodePointAt(char[], int) as it would have been available on a Java 1.4 JVM or on a later virtual machine version.
CodePointCount(String)

Return the number of characters in seq.

Fill(CharacterUtils.CharacterBuffer, TextReader)

Convenience method which calls Fill(buffer, reader, buffer.Buffer.Length).

Fill(CharacterUtils.CharacterBuffer, TextReader, Int32)

Fills the CharacterUtils.CharacterBuffer with characters read from the given reader System.IO.TextReader. This method tries to read 

numChars
characters into the CharacterUtils.CharacterBuffer, each call to fill will start filling the buffer from offset 0 up to numChars. In case code points can span across 2 java characters, this method may only fill numChars - 1 characters in order not to split in the middle of a surrogate pair, even if there are remaining characters in the System.IO.TextReader.

Depending on the LuceneVersion passed to GetInstance(LuceneVersion) this method implements supplementary character awareness when filling the given buffer. For all LuceneVersion > 3.0 Fill(CharacterUtils.CharacterBuffer, TextReader, Int32) guarantees that the given CharacterUtils.CharacterBuffer will never contain a high surrogate character as the last element in the buffer unless it is the last available character in the reader. In other words, high and low surrogate pairs will always be preserved across buffer boarders.

A return value of false means that this method call exhausted the reader, but there may be some bytes which have been read, which can be verified by checking whether buffer.Length > 0.

GetInstance(LuceneVersion)

Returns a CharacterUtils implementation according to the given LuceneVersion instance.
GetJava4Instance(LuceneVersion)

Return a CharacterUtils instance compatible with Java 1.4.

NewCharacterBuffer(Int32)

Creates a new CharacterUtils.CharacterBuffer and allocates a char[] of the given bufferSize.
OffsetByCodePoints(Char[], Int32, Int32, Int32, Int32)

Return the index within buf[start:start+count] which is by offset code points from index.

ToChars(Int32[], Int32, Int32, Char[], Int32)

Converts a sequence of unicode code points to a sequence of .NET characters.

ToCodePoints(Char[], Int32, Int32, Int32[], Int32)

Converts a sequence of .NET characters to a sequence of unicode code points.

ToLower(Char[], Int32, Int32)

Converts each unicode codepoint to lowerCase via ToLower(Int32) starting at the given offset.

ToUpper(Char[], Int32, Int32)

Converts each unicode codepoint to UpperCase via ToUpper(Int32) starting at the given offset.

Extension Methods