Text::Context::EitherSUser3Contributed Perl DocumeText::Context::EitherSide(3)NAMEText::Context::EitherSide - Get n words either side of search keywords
SYNOPSIS
use Text::Context::EitherSide;
my $text = "The quick brown fox jumped over the lazy dog";
my $context = Text::Context::EitherSide->new($text);
$context->as_string("fox") # "... quick brown fox jumped over ..."
$context->as_string("fox", "jumped")
# "... quick brown fox jumped over the ..."
my $context = Text::Context::EitherSide->new($text, context => 1);
# 1 word on either side
$context->as_string("fox", "jumped", "dog");
# "... brown fox jumped over ... lazy dog",
Or, if you don't believe in all this OO rubbish:
use Text::Context::EitherSideqw(get_context);
get_context(1, $text, "fox", "jumped", "dog")
# "... brown fox jumped over ... lazy dog"
DESCRIPTION
Suppose you have a large piece of text - typically, say, a web page or
a mail message. And now suppose you've done some kind of full-text
search on that text for a bunch of keywords, and you want to display
the context in which you found the keywords inside the body of the
text.
A simple-minded way to do that would be just to get the two words
either side of each keyword. But hey, don't be too simple minded,
because you've got to make sure that the list doesn't overlap. If you
have
the quick brown fox jumped over the lazy dog
and you extract two words either side of "fox", "jumped" and "dog", you
really don't want to end up with
quick brown fox jumped over brown fox jumped over the the lazy dog
so you need a small amount of smarts. This module has a small amount of
smarts.
EXPORTABLE
get_context
This is primarily an object-oriented module. If you don't care about
that, just import the "get_context" subroutine, and call it like so:
get_context($num_of_words, $text, @words_to_find)
and you'll get back a string with ellipses as in the synopsis. That's
all that most people need to know. But if you want to do clever
stuff...
METHODS
new
my $c = Text::Context::EitherSite->new($text [, context=> $n]);
Create a new object storing some text to be searched, plus optionally
some information about how many words on either side you want. (If you
don't like the default of 2.)
context
$c->context(5);
Allows you to get and set the number of the words on either side.
as_sparse_list
$c->as_sparse_list(@keywords)
Returns the keywords, plus n words on either side, as a sparse list;
the original text is split into an array of words, and non-contextual
elements are replaced with "undef"s. (That's not actually how it works,
but conceptually, it's the same.)
as_list
$c->as_list(@keywords)
The same as "as_sparse_list", but single or multiple "undef"s are
collapsed into a single ellipsis:
(undef, "foo", undef, undef, undef, "bar")
becomes
("...", "foo", "...", "bar")
as_string
$c->as_string(@keywords)
Takes the "as_list" output above and joins them all together into a
string. This is what most people want from "Text::Context::EitherSide".
EXPORT
"get_context" is available as a shortcut for
Text::Context::EitherSide->new($text, context => $n)->as_string(@words);
but needs to be explicitly imported. Nothing is exported by default.
SEE ALSO
Text::Context is an even smarter way of extracting a contextual string.
AUTHOR
Current maintainer: Tony Bowden
Original author: Simon Cozens
BUGS and QUERIES
Please direct all correspondence regarding this module to:
bug-Text-Context-EitherSide@rt.cpan.org
COPYRIGHT AND LICENSE
Copyright 2002-2005 by Kasei Limited, http://www.kasei.com/
You may use and redistribute this module under the terms of the
Artistic License 2.0.
http://www.perlfoundation.org/artistic_license_2_0
perl v5.14.1 2009-05-04 Text::Context::EitherSide(3)
