Bill Dueber > Library-CallNumber-LC-0.10 > Library::CallNumber::LC



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Module Version: 0.10   Source   Latest Release: Library-CallNumber-LC-0.23


Library::CallNumber::LC - Deal with Library-of-Congress call numbers


Version 0.10;


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 'A  012340C110'
    print $a->start_of_range; # same as "normalize"
    my $b = Library::CallNumber::LC->new('B11 .c13 .d11');
    print $b->normalize;
    # gives 'B  001100C130D110'
    my @range = ($a->start_of_range, $b->end_of_range);
    # end of range is 'B  001100C130D119~999'
    # 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:

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 - AZ9999.99. The end_of_range method pads the given call number out to three cutters if need be. There is no attempt to make end_of_range normalization correspond to anything in real life.


Regexp constants to deal with matching LC and variants


new =head2 new($lc) -- create a new object, optionally passing in the initial string

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:

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(string $lc, boolean $bottom, boolean $fulllength)

Base function to perform normalization. $bottomout, if true, forces a "range end". $fulllength determines if the return value should be padded all the way out.

normalize() -- normalize the callno in the current object as a sortable string =head2 normalize($lc) -- normalize the passed callno as a sortable string


Force normalization to return the full-length string (as opposed to the shortest possible string) for ease in converting to an int.

start_of_range (alias for normalize)

end_of_range($lc) -- downshift an lc number so it represents the end of a range

end_of_range_FullLength($lc) -- downshift to represent the end of a range, expanded out


Turn everything up to and including the second cutter into a long integer. Useful for fast range checks, although obviously not perfectly accurate.


Bill Dueber, <dueberb at>


Please report any bugs or feature requests through the web interface at 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:



Copyright 2009 Bill Dueber, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as the new BSD licsense as described at

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