Library::CallNumber::LC (3pm)

Version 0.22;

Utility functions to deal with Library of Congress Call Numbers

    use Library::CallNumber::LC;
    my $a = Library::CallNumber::LC->new('A 123.4 .c11');
    print $a->normalize; # normalizes for string comparisons.
    # gives 'A01234 C11'
    print $a->start_of_range; # same as "normalize"
    my $b = Library::CallNumber::LC->new('B11 .c13 .d11');
    print $b->normalize;
    # gives 'B0011 C13 D11'
    my @range = ($a->start_of_range, $b->end_of_range);
    # end of range is 'B0011 C13 D11~'

    # Get components suitable for printing (e.g., number and decimal joined, leading dot on first cutter)
    @comps = Library::CallNumber::LC->new('A 123.4 .c11')->components()

    # Same thing, but return empty strings for missing components (e.g., the cutters)
    @comps = Library::CallNumber::LC->new('A 123.4 .c11')->components('true');

Library::CallNumber::LC is mostly designed to do call number normalization, with the following goals:

• The normalized call numbers are comparable with each other, for proper sorting

• The normalized call number is a short as possible, so left-anchored wildcard searches are possible (e.g., searching on \*(L"A11*\*(R" should give you all the A11 call numbers)

• A range defined by start_of_range and end_of_range should be correct, assuming that the string given for the end of the range is, in fact, a left prefix.

That last point needs some explanation. The idea is that if someone gives a range of, say, A-AZ, what they really mean is A - \s-1AZ9999\s0.99. The end_of_range method generates a key which lies immediately beyond the last possible key for a given starting point. There is no attempt to make end_of_range normalization correspond to anything in real life.

call_number([call_number_text])

The text of the call number we are dealing with.

topper([character])

Specify which character occupies the 'always-sort-to-the-top' slots in the sort keys. Defaults to the \s-1SPACE\s0 character, but can reasonably be anything with an \s-1ASCII\s0 value lower than 48 (i.e. the 'zero' character, '0'). This can function as either a class or instance method depending on need.

bottomer([character])

Specify which character occupies the 'always-sort-to-the-bottom' slots in the sort keys. Defaults to the \s-1TILDE\s0 character, but can reasonably be anything with an \s-1ASCII\s0 value higher than 90 (i.e. 'Z'). This can function as either a class or instance method depending on need.

components(boolean returnAll = false)

@comps = Library::CallNumber::LC->new('A 123.4 .c11')->components($returnAll)

Returns an array of the individual components of the call number (or undef if it doesn't look like a call number). Components are:

• alpha

• number (numeric.decimal)

• cutter1

• cutter2

• cutter3

• \*(L"extra\*(R" (anything after the cutters)

The optional argument <I returnAll> (false by default) determines whether or not empty components (e.g., extra cutters) get a slot in the returned list.

_normalize(call_number_text)

Base function to perform normalization.

normalize([call_number_text])

Normalize the stored or passed call number as a sortable string

start_of_range([call_number_text])

Alias for normalize

end_of_range([call_number_text])

Downshift an lc number so it represents the end of a range

toLongInt(call_number_text, num_digits)

Attempt to turn a call number into an integer value. Possibly useful for fast range checks, although obviously not perfectly accurate. Optional argument $num_digits can be used to control the number of digits used, and therefore the precision of the results.

Current Maintainer: Dan Wells, \*(C`<dbw2 at calvin.edu>\*(C' Original Author: Bill Dueber, \*(C`<dueberb at umich.edu>\*(C'

Please report any bugs or feature requests through the web interface at http://code.google.com/p/library-callnumber-lc/issues/list <http://code.google.com/p/library-callnumber-lc/issues/list>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

You can find documentation for this module with the perldoc command.

perldoc Library::CallNumber::LC

You can also look for information at the Google Code page:

http://code.google.com/p/library-callnumber-lc/

Copyright 2009 Bill Dueber, all rights reserved. Copyright 2011 Dan Wells, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself and also under the new \s-1BSD\s0 license as described at http://www.opensource.org/licenses/bsd-license.php