Class WordDelimiterFilter

All Implemented Interfaces:
Closeable, AutoCloseable, Unwrappable<TokenStream>

@Deprecated public final class WordDelimiterFilter extends TokenFilter
Deprecated.
Use WordDelimiterGraphFilter instead: it produces a correct token graph so that e.g. PhraseQuery works correctly when it's used in the search time analyzer.
Splits words into subwords and performs optional transformations on subword groups. Words are split into subwords with the following rules:
  • split on intra-word delimiters (by default, all non alpha-numeric characters): "Wi-Fi""Wi", "Fi"
  • split on case transitions: "PowerShot""Power", "Shot"
  • split on letter-number transitions: "SD500""SD", "500"
  • leading and trailing intra-word delimiters on each subword are ignored: "//hello---there, 'dude'""hello", "there", "dude"
  • trailing "'s" are removed for each subword: "O'Neil's" "O", "Neil"
    • Note: this step isn't performed in a separate filter because of possible subword combinations.
The GENERATE... options affect how incoming tokens are broken into parts, and the various CATENATE_... parameters affect how those parts are combined.
  • If no CATENATE option is set, then no subword combinations are generated: "PowerShot" 0:"Power", 1:"Shot" (0 and 1 are the token positions)
  • CATENATE_WORDS means that in addition to the subwords, maximum runs of non-numeric subwords are catenated and produced at the same position of the last subword in the run:
    • "PowerShot"0:"Power", 1:"Shot" 1:"PowerShot"
    • "A's+B's&C's" > 0:"A", 1:"B", 2:"C", 2:"ABC"
    • "Super-Duper-XL500-42-AutoCoder!" 0:"Super", 1:"Duper", 2:"XL", 2:"SuperDuperXL", 3:"500" 4:"42", 5:"Auto", 6:"Coder", 6:"AutoCoder"
  • CATENATE_NUMBERS works like CATENATE_WORDS, but for adjacent digit sequences.
  • CATENATE_ALL smushes together all the token parts without distinguishing numbers and words.
One use for WordDelimiterFilter is to help match words with different subword delimiters. For example, if the source text contained "wi-fi" one may want "wifi" "WiFi" "wi-fi" "wi+fi" queries to all match. One way of doing so is to specify CATENATE options in the analyzer used for indexing, and not in the analyzer used for querying. Given that the current StandardTokenizer immediately removes many intra-word delimiters, it is recommended that this filter be used after a tokenizer that does not do this (such as WhitespaceTokenizer).
  • Field Details

    • LOWER

      public static final int LOWER
      Deprecated.
      See Also:
    • UPPER

      public static final int UPPER
      Deprecated.
      See Also:
    • DIGIT

      public static final int DIGIT
      Deprecated.
      See Also:
    • SUBWORD_DELIM

      public static final int SUBWORD_DELIM
      Deprecated.
      See Also:
    • ALPHA

      public static final int ALPHA
      Deprecated.
      See Also:
    • ALPHANUM

      public static final int ALPHANUM
      Deprecated.
      See Also:
    • GENERATE_WORD_PARTS

      public static final int GENERATE_WORD_PARTS
      Deprecated.
      Causes parts of words to be generated:

      "PowerShot" => "Power" "Shot"

      See Also:
    • GENERATE_NUMBER_PARTS

      public static final int GENERATE_NUMBER_PARTS
      Deprecated.
      Causes number subwords to be generated:

      "500-42" => "500" "42"

      See Also:
    • CATENATE_WORDS

      public static final int CATENATE_WORDS
      Deprecated.
      Causes maximum runs of word parts to be catenated:

      "wi-fi" => "wifi"

      See Also:
    • CATENATE_NUMBERS

      public static final int CATENATE_NUMBERS
      Deprecated.
      Causes maximum runs of word parts to be catenated:

      "500-42" => "50042"

      See Also:
    • CATENATE_ALL

      public static final int CATENATE_ALL
      Deprecated.
      Causes all subword parts to be catenated:

      "wi-fi-4000" => "wifi4000"

      See Also:
    • PRESERVE_ORIGINAL

      public static final int PRESERVE_ORIGINAL
      Deprecated.
      Causes original words are preserved and added to the subword list (Defaults to false)

      "500-42" => "500" "42" "500-42"

      See Also:
    • SPLIT_ON_CASE_CHANGE

      public static final int SPLIT_ON_CASE_CHANGE
      Deprecated.
      If not set, causes case changes to be ignored (subwords will only be generated given SUBWORD_DELIM tokens)
      See Also:
    • SPLIT_ON_NUMERICS

      public static final int SPLIT_ON_NUMERICS
      Deprecated.
      If not set, causes numeric changes to be ignored (subwords will only be generated given SUBWORD_DELIM tokens).
      See Also:
    • STEM_ENGLISH_POSSESSIVE

      public static final int STEM_ENGLISH_POSSESSIVE
      Deprecated.
      Causes trailing "'s" to be removed for each subword

      "O'Neil's" => "O", "Neil"

      See Also:
    • IGNORE_KEYWORDS

      public static final int IGNORE_KEYWORDS
      Deprecated.
      Suppresses processing terms with KeywordAttribute.isKeyword()=true.
      See Also:
  • Constructor Details

    • WordDelimiterFilter

      public WordDelimiterFilter(TokenStream in, byte[] charTypeTable, int configurationFlags, CharArraySet protWords)
      Deprecated.
      Creates a new WordDelimiterFilter
      Parameters:
      in - TokenStream to be filtered
      charTypeTable - table containing character types
      configurationFlags - Flags configuring the filter
      protWords - If not null is the set of tokens to protect from being delimited
    • WordDelimiterFilter

      public WordDelimiterFilter(TokenStream in, int configurationFlags, CharArraySet protWords)
      Deprecated.
      Creates a new WordDelimiterFilter using WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE as its charTypeTable
      Parameters:
      in - TokenStream to be filtered
      configurationFlags - Flags configuring the filter
      protWords - If not null is the set of tokens to protect from being delimited
  • Method Details