Stop words for several languages.
use Lingua::StopWords qw( getStopWords );
my $stopwords = getStopWords('en');
my @words = qw( i am the walrus goo goo g'joob );
# prints "walrus goo goo g'joob"
print join ' ', grep { !$stopwords->{$_} } @words;
In keyword search, it is common practice to suppress a collection of \*(L"stopwords\*(R": words such as \*(L"the\*(R", \*(L"and\*(R", \*(L"maybe\*(R", etc. which exist in in a large number of documents and do not tell you anything important about any document which contains them. This module provides such \*(L"stoplists\*(R" in several languages.
|-----------------------------------------------------------| | Language | ISO code | default encoding | also available | |-----------------------------------------------------------| | Danish | da | ISO-8859-1 | UTF-8 | | Dutch | nl | ISO-8859-1 | UTF-8 | | English | en | ISO-8859-1 | UTF-8 | | Finnish | fi | ISO-8859-1 | UTF-8 | | French | fr | ISO-8859-1 | UTF-8 | | German | de | ISO-8859-1 | UTF-8 | | Hungarian | hu | ISO-8859-1 | UTF-8 | | Italian | it | ISO-8859-1 | UTF-8 | | Norwegian | no | ISO-8859-1 | UTF-8 | | Portuguese | pt | ISO-8859-1 | UTF-8 | | Spanish | es | ISO-8859-1 | UTF-8 | | Swedish | sv | ISO-8859-1 | UTF-8 | | Russian | ru | KOI8-R | UTF-8 | |-----------------------------------------------------------|
my $stoplist = getStopWords('en'); my $utf8_stoplist = getStopWords('en', 'UTF-8');
Retrieve a stoplist in the form of a hashref where the keys are all stopwords and the values are all 1.
$stoplist = { and => 1, if => 1, # ... };
getStopWords() expects 1-2 arguments. The first, which is required, is an \s-1ISO\s0 code representing a supported language. If the \s-1ISO\s0 code cannot be found, getStopWords returns undef.
The second argument should be '\s-1UTF-8\s0' if you want the stopwords encoded in \s-1UTF-8\s0. The \s-1UTF-8\s0 flag will be turned on, so make sure you understand all the implications of that.
The stoplists supplied by this module were created as part of the Snowball project (see <http://snowball.tartarus.org>, Lingua::Stem::Snowball).
Lingua::EN::StopWords provides a different stoplist for English.
Maintained by Marvin Humphrey <marvin at rectangular dot com>. Original author Fabien Potencier, <fabpot at cpan dot org>.
Copyright 2004-2008 Fabien Potencier, Marvin Humphrey
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.3 or, at your option, any later version of Perl 5 you may have available.