Package org.apache.lucene.analysis.standard

# Class StandardTokenizerImpl

java.lang.Object
org.apache.lucene.analysis.standard.StandardTokenizerImpl

public final class StandardTokenizerImpl extends Object
This class implements Word Break rules from the Unicode Text Segmentation algorithm, as specified in Unicode Standard Annex #29.

Tokens produced are of the following types:

- <ALPHANUM>: A sequence of alphabetic and numeric characters
- <NUM>: A number
- <SOUTHEAST_ASIAN>: A sequence of characters from South and Southeast Asian languages, including Thai, Lao, Myanmar, and Khmer
- <IDEOGRAPHIC>: A single CJKV ideographic character
- <HIRAGANA>: A single hiragana character
- <KATAKANA>: A sequence of katakana characters
- <HANGUL>: A sequence of Hangul characters
- <EMOJI>: A sequence of Emoji characters

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final int`
  `EMOJI_TYPE`
  Emoji token type
  `static final int`
  `HANGUL_TYPE`
  Hangul token type
  `static final int`
  `HIRAGANA_TYPE`
  Hiragana token type
  `static final int`
  `IDEOGRAPHIC_TYPE`
  Ideographic token type
  `static final int`
  `KATAKANA_TYPE`
  Katakana token type
  `static final int`
  `NUMERIC_TYPE`
  Numbers
  `static final int`
  `SOUTH_EAST_ASIAN_TYPE`
  Chars in class \p{Line_Break = Complex_Context} are from South East Asian scripts (Thai, Lao, Myanmar, Khmer, etc.).
  `static final int`
  `WORD_TYPE`
  Alphanumeric sequences
  `static final int`
  `YYEOF`
  This character denotes the end of file.
  `static final int`
  `YYINITIAL`
  Lexical States.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `StandardTokenizerImpl(Reader in)`
  Creates a new scanner

- ## Method Summary

  Modifier and Type
  Method
  Description
  `int`
  `getNextToken()`
  Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
  `final void`
  `getText(CharTermAttribute t)`
  Fills CharTermAttribute with the current token text.
  `final void`
  `setBufferSize(int numChars)`
  Sets the scanner buffer size in chars
  `final boolean`
  `yyatEOF()`
  Returns whether the scanner has reached the end of the reader it reads from.
  `final void`
  `yybegin(int newState)`
  Enters a new lexical state.
  `final int`
  `yychar()`
  Character count processed so far
  `final char`
  `yycharat(int position)`
  Returns the character at the given position from the matched text.
  `final void`
  `yyclose()`
  Closes the input reader.
  `final int`
  `yylength()`
  How many characters were matched.
  `void`
  `yypushback(int number)`
  Pushes the specified amount of characters back into the input stream.
  `final void`
  `yyreset(Reader reader)`
  Resets the scanner to read from a new input stream.
  `final int`
  `yystate()`
  Returns the current lexical state.
  `final String`
  `yytext()`
  Returns the text matched by the current regular expression.

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Field Details

  - ### YYEOF

    public static final int YYEOF
    This character denotes the end of file.
    See Also:
      - Constant Field Values

  - ### YYINITIAL

    public static final int YYINITIAL
    Lexical States.
    See Also:
      - Constant Field Values

  - ### WORD_TYPE

    public static final int WORD_TYPE
    Alphanumeric sequences
    See Also:
      - Constant Field Values

  - ### NUMERIC_TYPE

    public static final int NUMERIC_TYPE
    Numbers
    See Also:
      - Constant Field Values

  - ### SOUTH_EAST_ASIAN_TYPE

    public static final int SOUTH_EAST_ASIAN_TYPE
    Chars in class \p{Line_Break = Complex_Context} are from South East Asian scripts (Thai, Lao, Myanmar, Khmer, etc.). Sequences of these are kept together as as a single token rather than broken up, because the logic required to break them at word boundaries is too complex for UAX#29.

    See Unicode Line Breaking Algorithm: http://www.unicode.org/reports/tr14/#SA

    See Also:
      - Constant Field Values

  - ### IDEOGRAPHIC_TYPE

    public static final int IDEOGRAPHIC_TYPE
    Ideographic token type
    See Also:
      - Constant Field Values

  - ### HIRAGANA_TYPE

    public static final int HIRAGANA_TYPE
    Hiragana token type
    See Also:
      - Constant Field Values

  - ### KATAKANA_TYPE

    public static final int KATAKANA_TYPE
    Katakana token type
    See Also:
      - Constant Field Values

  - ### HANGUL_TYPE

    public static final int HANGUL_TYPE
    Hangul token type
    See Also:
      - Constant Field Values

  - ### EMOJI_TYPE

    public static final int EMOJI_TYPE
    Emoji token type
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### StandardTokenizerImpl

    public StandardTokenizerImpl(Reader in)
    Creates a new scanner
    Parameters:
      `in` - the java.io.Reader to read input from.

- ## Method Details

  - ### yychar

    public final int yychar()
    Character count processed so far

  - ### getText

    public final void getText(CharTermAttribute t)
    Fills CharTermAttribute with the current token text.

  - ### setBufferSize

    public final void setBufferSize(int numChars)
    Sets the scanner buffer size in chars

  - ### yyclose

    public final void yyclose() throws IOException
    Closes the input reader.
    Throws:
      `IOException` - if the reader could not be closed.

  - ### yyreset

    public final void yyreset(Reader reader)
    Resets the scanner to read from a new input stream.

    Does not close the old reader.

    All internal variables are reset, the old input stream cannot be reused (internal buffer is discarded and lost). Lexical state is set to `ZZ_INITIAL`.

    Internal scan buffer is resized down to its initial length, if it has grown.

    Parameters:
      `reader` - The new input stream.

  - ### yyatEOF

    public final boolean yyatEOF()
    Returns whether the scanner has reached the end of the reader it reads from.
    Returns:
      whether the scanner has reached EOF.

  - ### yystate

    public final int yystate()
    Returns the current lexical state.
    Returns:
      the current lexical state.

  - ### yybegin

    public final void yybegin(int newState)
    Enters a new lexical state.
    Parameters:
      `newState` - the new lexical state

  - ### yytext

    public final String yytext()
    Returns the text matched by the current regular expression.
    Returns:
      the matched text.

  - ### yycharat

    public final char yycharat(int position)
    Returns the character at the given position from the matched text.

    It is equivalent to `yytext().charAt(pos)`, but faster.

    Parameters:
      `position` - the position of the character to fetch. A value from 0 to `yylength()-1`.
    Returns:
      the character at `position`.

  - ### yylength

    public final int yylength()
    How many characters were matched.
    Returns:
      the length of the matched text region.

  - ### yypushback

    public void yypushback(int number)
    Pushes the specified amount of characters back into the input stream.

    They will be read again by then next call of the scanning method.

    Parameters:
      `number` - the number of characters to be read again. This number must not be greater than `yylength()`.

  - ### getNextToken

    public int getNextToken() throws IOException
    Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
    Returns:
      the next token.
    Throws:
      `IOException` - if any I/O-Error occurs.