NAME

       Lucy::Analysis::SnowballStopFilter - Suppress a "stoplist" of common words.

SYNOPSIS

           my $stopfilter = Lucy::Analysis::SnowballStopFilter->new(
               language => 'fr',
           );
           my $polyanalyzer = Lucy::Analysis::PolyAnalyzer->new(
               analyzers => [ $case_folder, $tokenizer, $stopfilter, $stemmer ],
           );

DESCRIPTION

       A "stoplist" is collection of "stopwords": words which are common enough to be of little
       value when determining search results.  For example, so many documents in English contain
       "the", "if", and "maybe" that it may improve both performance and relevance to block them.

       Before filtering stopwords:

           ("i", "am", "the", "walrus")

       After filtering stopwords:

           ("walrus")

       SnowballStopFilter provides default stoplists for several languages, courtesy of the
       Snowball project (<http://snowball.tartarus.org>), or you may supply your own.

           |-----------------------|
           | ISO CODE | LANGUAGE   |
           |-----------------------|
           | da       | Danish     |
           | de       | German     |
           | en       | English    |
           | es       | Spanish    |
           | fi       | Finnish    |
           | fr       | French     |
           | hu       | Hungarian  |
           | it       | Italian    |
           | nl       | Dutch      |
           | no       | Norwegian  |
           | pt       | Portuguese |
           | sv       | Swedish    |
           | ru       | Russian    |
           |-----------------------|

CONSTRUCTORS

   new( [labeled params] )
           my $stopfilter = Lucy::Analysis::SnowballStopFilter->new(
               language => 'de',
           );

           # or...
           my $stopfilter = Lucy::Analysis::SnowballStopFilter->new(
               stoplist => \%stoplist,
           );

       •   stoplist - A hash with stopwords as the keys.

       •   language - The ISO code for a supported language.

INHERITANCE

       Lucy::Analysis::SnowballStopFilter isa Lucy::Analysis::Analyzer isa Lucy::Object::Obj.