NAME

MARC::Charset::Compiler - compile XML mapping rules from LoC

SYNOPSIS

$compiler = MARC::Charset::Compiler->new();
$table = $compiler->compile('codetables.xml');

DESCRIPTION

MARC::Charset uses mapping rules from the Library of Congress for generating a MARC::Charset::Table for looking up utf8 values based on the source MARC-8 character set and the character.

DATA SOURCE

The XML mapping files this module compiles (etc/codetables.xml, etc/additional-iii-characters.xml, etc/cccii.xml in this distribution) originate from the Library of Congress's own published character set tables:

https://www.loc.gov/marc/specifications/codetables.xml

That file is not treated as a live dependency, and this module never fetches it at install or run time -- the copy in etc/ is vendored and versioned with the distribution. It's also known to differ from whatever the LC URL currently serves: LC has published more than one revision of this file over the years, and the copy here has picked up maintainer corrections for at least one known mistake in LC's data (see the G0/G1 workaround in end_element() below, for characterSet codes 51, 34 and 45). Diffing against the live URL is useful context when investigating a specific character mapping, but copying it over etc/codetables.xml wholesale is not safe without re-checking that those corrections are still needed against whatever LC is serving at the time.

METHODS

new()

The constructor.

compile()

Pass in the path to an XML file to compile.