=pod

=head1 NAME

Locale::Codes - a distribution of modules to handle locale codes

=head1 DESCRIPTION

B<Locale-Codes> is a distribution containing a set of modules designed
to work with sets of codes which uniquely identify something.  For
example, there are codes associated with different countries, different
currencies, different languages, etc.  These sets of codes are typically
maintained in some standard.

This distribution provides a way to work with these lists of codes.
Because the data from the various standards is not available in any
sort of consistent API, access to the lists is not available in any
direct fashion.  To compensate for this, the list of codes is stored
internally within this distribution, and the distribution is updated
on a regular basis to include all known codes at that point in time.
This does mean that it is necessary to keep this distribution
up-to-date to keep up with the various changes that are made in the
various standards.

Traditionally, a module has been created to work with each type of
code sets.  So, there is a module for working with country lists, one
for currency lists, etc.  Since version 3.00, all of these individual
modules were written as wrappers around a central module (which was not
intended to be used directly) which did all of the real work.

Starting with version 3.50, the central module was reworked slightly
to provide an object-oriented interface.  All of the modules for
working with individual types of code sets were reworked to use the
improved OO module, so the traditional interfaces still work as they
always have.  As a result, you are free to use the traditional
functional (non-OO) interfaces, or to use the OO interface and bypass
the wrapper modules entirely.

Both methods will be supported in the future, so use the one that is
best suited to your needs.

Within each type, any number of code sets are allowed.  For example,
sets of country codes are maintained in several different locations
including the ISO-3166 standard, the IANA, and by the United Nations.
The lists of countries are similar, but not identical.  Multiple code
sets are supported, though trying to convert from one code set to
another will not always work since the list of countries is not
one-to-one.

All data in all of these modules comes directly from the original
standards (or as close to direct as possible), so it should be
up-to-date at the time of release.

I plan on releasing a new version several times a year to incorporate
any changes made in the standards. However, I don't always know about
changes that occur, so if any of the standards change, and you want a
new release sooner, just email me and I'll get one out.

=head1 SYNOPSIS (OBJECT-ORIENTED INTERFACE)

   use Locale::Codes;
   or
   use Locale::Codes ':constants';

   $obj = new Locale::Codes 'country';

=head1 OBJECT-ORIENTED METHODS

The following methods are available.

In all methods, when specifying a code set, the name (as a string)
is always available.

Traditionally, you could also use a perl constant to specify the
code set.  In order to do so with the OO interface, you have to
import the constants.  To do that, load the module with:

   use Locale::Codes ':constants';

=over 4

=item B<new ( [TYPE [,CODESET]] )>

   $obj = new Locale::Codes;
   $obj = new Locale::Codes 'country';
   $obj = new Locale::Codes 'country','alpha-3';
   $obj = new Locale::Codes 'country',LOCALE_COUNTRY_ALPHA_3;

This creates a new object that can access the data.  If no type is specified
(in the first argument), you must use the B<type> method described below.
No operations will work unless the type is specified.

The second argument is the default code set to use.  This is optional, as
each type has a default code set.  The default code set can be set using
the B<codeset> method below.

The last example is only available if the constants were imported when
the module was loaded.

=item B<show_errors ( FLAG )>

   $obj->show_errors(1);
   $obj->show_errors(0);

By default, error messages will be produced when bad data is passed
to any method.  By passing in '0', these will be turned off so that
all failures will be silent.

=item B<type ( TYPE )>

   $obj->type($type)

This will set the type of codes that will be worked with.  C<$type> may
be any of the recognized types of code sets, including:

   country
   language
   currency
   script
   etc.

The list of valid types, and the code sets supported in each, are described
in the L<Locale::Codes::Types> document.

This method can be called any number of times to toggle between different types
of code sets.

=item B<codeset ( CODESET )>

   $obj->codeset($codeset);

This sets the default code set to use.  The list of code sets available
for each type are described in the L<Locale::Codes::Types> document.

In all other methods below, when an optional B<CODESET> argument is
omitted, it will default to this value.

=item B<code2name ( CODE [,CODESET] [,'retired'] )>

   $name = $obj->code2name($code [,$codeset] [,'retired']);

This functions take a code and returns a string which contains
the name of the element identified.  If the code is not a valid
code in the B<CODESET> specified then C<undef> will be returned.

The name of the element is the name as specified in the standard,
and as a result, different variations of an element name may
be returned for different values of B<CODESET>.

For example, the alpha-2 country code set defines the two-letter
code "bo" to be "Bolivia, Plurinational State of", whereas the
alpha-3 code set defines the code 'bol' to be the country "Bolivia
(Plurinational State of)". So:

   $obj->code2name('bo','alpha-2');
      => 'Bolivia, Plurinational State of'

   $obj->code2name('bol','alpha-3');
      => 'Bolivia (Plurinational State of)'

By default, only active codes will be used, but if the string
'retired' is passed in as an argument, both active and retired
codes will be examined.

=item B<name2code ( NAME [,CODESET] [,'retired'] )>

   $code = $obj->name2code($name [,$codeset] [,'retired']);

This function takes the name of an element (or any of it's aliases)
and returns the code that corresponds to it, if it exists. If B<NAME>
could not be identified as the name of one of the elements, then
C<undef> will be returned.

The name is not case sensitive. Also, any known variation of a name
may be passed in.

For example, even though the country name returned using 'alpha-2'
and 'alpha-3' country codes for Bolivia are different, either country
name may be passed in since for each code set (in addition to the more
common alias 'Bolivia'). So:

   $obj->name2code('Bolivia, Plurinational State of','alpha-2');
      => bo

   $obj->name2code('Bolivia (Plurinational State of)','alpha-2');
      => bo

   $obj->name2code('Bolivia','alpha-2');
      => bo

By default, only active names will be used, but if the string
'retired' is passed in as an argument, both active and retired
names will be examined.

=item B<code2code ( CODE [,CODESET] ,CODESET2 )>

   $code = $obj->code2code($code [,$codeset] ,$codeset2);

This function takes a code from one code set (B<CODESET> or the
default code set), and returns the corresponding code from another
code set (B<CODESET2>). B<CODE> must exists in the code set specified
by B<CODESET> and must have a corresponding code in the
code set specified by B<CODESET2> or C<undef> will be returned.

   $obj->code2code('fin','alpha-3','alpha-2');
      => 'fi'

Note that this function does NOT support retired codes.

=item B<all_codes ( [CODESET] [,'retired'] )>

   @code = $obj->all_codes([$codeset] [,'retired']);

This returns a list of all code in the code set. The codes will be
sorted.

By default, only active codes will be returned, but if the string
'retired' is passed in as an argument, both active and retired
codes will be returned.

=item B<all_names ( [CODESET] [,'retired'] )>

   @name = $obj->all_names([$codeset] [,'retired']);

This method returns a list of all elements names for which there is a
corresponding code in the specified code set.

The names returned are exactly as they are specified in the standard,
and are sorted.

Since not all elements are listed in all code sets, the list of
elements may differ depending on the code set specified.

By default, only active names will be returned, but if the string
'retired' is passed in as an argument, both active and retired
names will be returned.

=back

The following additional methods are available and can be used to
modify the code list data (and are therefore not generally useful).

=over 4

=item B<rename_code  ( CODE ,NEW_NAME [,CODESET] )>

   $flag = $obj->rename_code($code,$new_name [,$codeset]);

This method can be used to change the official name of an element. At
that point, the name returned by the C<code2name> method would be
B<NEW_NAME> instead of the name specified in the standard.

The original name will remain as an alias.

For example, the official country name for code 'gb' is 'United
Kingdom'.  If you want to change that, you might call:

   $obj->rename_code('gb', 'Great Britain');

This means that calling code2name('gb') will now return 'Great
Britain' instead of 'United Kingdom'.

If any error occurs, a warning is issued and 0 is returned. An error
occurs if B<CODE> doesn't exist in the specified code set, or if
B<NEW_NAME> is already in use but for a different element.

If the method succeeds, 1 is returned.

=item B<add_code  ( CODE ,NAME [,CODESET] )>

   $flag = $obj->add_code($code,$name [,$codeset]);

This method is used to add a new code and name to the data.

Both B<CODE> and B<NAME> must be unused in the data set or an error
occurs (though B<NAME> may be used in a different data set).

For example, to create the fictitious country named "Duchy of
Grand Fenwick" with codes "gf" and "fen", use the following:

   $obj->add_code("fe","Duchy of Grand Fenwick",'alpha-2');
   $obj->add_code("fen","Duchy of Grand Fenwick",'alpha-3');

The return value is 1 on success, 0 on an error.

=item B<delete_code  ( CODE [,CODESET] )>

   $flag = $obj->delete_code($code [,$codeset]);

This method is used to delete a code from the data.

B<CODE> must refer to an existing code in the code set.

The return value is 1 on success, 0 on an error.

=item B<add_alias  ( NAME ,NEW_NAME )>

   $flag = $obj->add_alias($name,$new_name);

This method is used to add a new alias to the data. They do
not alter the return value of the C<code2name> function.

B<NAME> must be an existing element name, and B<NEW_NAME> must
be unused or an error occurs.

The return value is 1 on success, 0 on an error.

=item B<delete_alias  ( NAME )>

   $flag = $obj->delete_alias($name);

This method is used to delete an alias from the data. Once
removed, the element may not be referred to by B<NAME>.

B<NAME> must be one of a list of at least two names that may be used to
specify an element. If the element may only be referred to by a single
name, you'll need to use the C<add_alias> method to add a new alias
first, or the C<remove_code> method to remove the element entirely.

If the alias is used as the name in any code set, one of the other
names will be used instead. Predicting exactly which one will
be used requires you to know the order in which the standards
were read, which is not reliable, so you may want to use the
C<rename_code> method to force one of the alternate names to be
used.

The return value is 1 on success, 0 on an error.

=item B<replace_code  ( CODE ,NEW_CODE [,CODESET] )>

   $flag = $obj->replace_code($code,$new_code [,$codeset]);

This method is used to change the official code for an element. At
that point, the code returned by the C<name2code> method would be
B<NEW_CODE> instead of the code specified in the standard.

B<NEW_CODE> may either be a code that is not in use, or it may be an
alias for B<CODE> (in which case, B<CODE> becomes and alias and B<NEW_CODE>
becomes the "real" code).

The original code is kept as an alias, so that the C<code2name> routines
will work with either the code from the standard or the new code.

However, the C<all_codes> method will only return the codes which
are considered "real" (which means that the list of codes will now
contain B<NEW_CODE>, but will not contain B<CODE>).

=item B<add_code_alias  ( CODE ,NEW_CODE [,CODESET] )>

   $flag = $obj->add_code_alias($code,$new_code [,$codeset]);

This method adds an alias for the code. At that point, B<NEW_CODE> and B<CODE>
will both work in the C<code2name> method. However, the C<name2code> method will
still return the original code.

=item B<delete_code_alias  ( CODE [,CODESET] )>

These routines delete an alias for the code.

These will only work if B<CODE> is actually an alias. If it is the "real"
code, it will not be deleted. You will need to use the C<rename_code>
method to switch the real code with one of the aliases, and then
delete the alias.

=back

=head1 TRADITIONAL INTERFACES

In addition the the primary OO module, the following modules are included in
the distribution for the traditional way of working with code sets.

Each module will work with one specific type of code sets.

=over 4

=item L<Locale::Codes::Country>, L<Locale::Country>

This includes support for country codes (such as those listed in ISO-3166)
to specify the country.

Because this module was originally distributed as L<Locale::Country>, it is
also available under that name.

=item L<Locale::Codes::Language>, L<Locale::Language>

This includes support for language codes (such as those listed in ISO-639)
to specify the language.

Because this module was originally distributed as L<Locale::Language>, it is
also available under that name.

=item L<Locale::Codes::Currency>, L<Locale::Currency>

This includes support for currency codes (such as those listed in ISO-4217)
to specify the currency.

Because this module was originally distributed as L<Locale::Currency>, it is
also available under that name.

=item L<Locale::Codes::Script>, L<Locale::Script>

This includes support for script codes (such as those listed in ISO-15924)
to specify the script.

Because this module was originally distributed as L<Locale::Script>, it is
also available under that name.

=item L<Locale::Codes::LangExt>

This includes support for language extension codes (such as those listed
in the IANA language registry) to specify the language extension.

=item L<Locale::Codes::LangVar>

This includes support for language variation codes (such as those listed
in the IANA language registry) to specify the language variation.

=item L<Locale::Codes::LangFam>

This includes support for language family codes (such as those listed
in ISO 639-5) to specify families of languages.

=back

In addition to the modules above, there are a number of support modules included
in the distribution.  Any module not listed above falls into that category.

These modules are not intended to be used by programmers. They contain functions
or data that are used by the modules listed above.  No support of any kind is
offered for using these modules directly.  They may be modified at any time.

=head1 COMMON ALIASES

As of version 2.00, the modules supported common variants of names.

For example, Locale::Country supports variant names for countries, and
a few of the most common ones are included in the data. The country
code for "United States" is "us", so:

   country2code('United States');
     => "us"

Now the following will also return 'us':

   country2code('United States of America');
   country2code('USA');

Any number of common aliases may be included in the data, in addition
to the names that come directly from the standards.  If you have a
common alias for a country, language, or any other of the types of
codes, let me know and I'll add it, with some restrictions.

For example, the country name "North Korea" never appeared in any of
the official sources (instead, it was "Korea, North" or "Korea,
Democratic People's Republic of". I would honor a request to add an
alias "North Korea" since that's a very common way to specify the
country (please don't request this... I've already added it).

On the other hand, a request to add Zaire as an alias for "Congo, The
Democratic Republic of" will not be honored. The country's official
name is no longer Zaire, so adding it as an alias violates the
standard.  Zaire was kept as an alias in versions of this module prior
to 3.00, but it has been removed. Other aliases (if any) which no
longer appear in any standard (and which are not common variations of
the name in the standards) have also been removed.

=head1 RETIRED CODES

Occasionally, a code is deprecated, but it may still be desirable to
have access to it.

Although there is no way to see every code that has ever existed and
been deprecated (since most codesets do not have that information
available), as of version 3.20, every code which has ever been included
in these modules can be referenced.

For more information, refer to the documentation on the code2name, name2code,
all_codes, and all_names methods above.

=head1 SEE ALSO

=over 4

=item L<Locale::Codes::Types>

The list of all code sets available for each type.

=item L<Locale::Codes::Changes>

A history of changes made to this distribution.

=back

=head1 KNOWN BUGS AND LIMITATIONS

=over 4

=item B<Relationship between code sets>

Because each code set uses a slightly different list of elements, and
they are not necessarily one-to-one, there may be some confusion
about the relationship between codes from different code sets.

For example, ISO 3166 assigns one code to the country "United States
Minor Outlying Islands", but the IANA codes give different codes
to different islands (Baker Island, Howland Island, etc.).

This may cause some confusion... I've done the best that I could do
to minimize it.

=item B<Non-ASCII characters not supported>

Currently all names must be all ASCII. I plan on relaxing that
limitation in the future.

=back

=head1 BUGS AND QUESTIONS

If you find a bug in Locale::Codes, there are three ways to send it to me.
Any of them are fine, so use the method that is easiest for you.

=over 4

=item Direct email

You are welcome to send it directly to me by email.  The email address
to use is:  sbeck@cpan.org.

=item CPAN Bug Tracking

You can submit it using the CPAN tracking too.  This can be done at the
following URL:

L<http://rt.cpan.org/Public/Dist/Display.html?Name=Locale-Codes>

=item GitHub

You can submit it as an issue on GitHub.  This can be done at the following
URL:

L<https://github.com/SBECK-github/Locale-Codes>

=back

Please do not use other means to report bugs (such as forums for a specific
OS or Linux distribution) as it is impossible for me to keep up with all of
them.

When filing a bug report, please include the following information:

=over 4

=item B<Locale::Codes version>

Please include the version of Locale::Codes you are using.  You can get
this by using the script:

   use Locale::Codes;
   print $Locale::Codes::VERSION,"\n";

=back

If you want to report missing or incorrect codes, you must be running the
most recent version of Locale::Codes.

If you find any problems with the documentation (errors, typos, or items
that are not clear), please send them to me. I welcome any suggestions
that will allow me to improve the documentation.

=head1 AUTHOR

Locale::Country and Locale::Language were originally written by Neil
Bowers at the Canon Research Centre Europe (CRE). They maintained the
distribution from 1997 to 2001.

Locale::Currency was originally written by Michael Hennecke and was
modified by Neil Bowers for inclusion in the distribution.

From 2001 to 2004, maintenance was continued by Neil Bowers.  He
modified Locale::Currency for inclusion in the distribution. He also
added Locale::Script.

From 2004-2009, the module was unmaintained.

In 2010, maintenance was taken over by Sullivan Beck (sbeck@cpan.org)
with Neil Bower's permission.  All problems or comments should be
sent to him using any of the methods listed above.

=head1 COPYRIGHT

   Copyright (c) 1997-2001 Canon Research Centre Europe (CRE).
   Copyright (c) 2001      Michael Hennecke (Locale::Currency)
   Copyright (c) 2001-2010 Neil Bowers
   Copyright (c) 2010-2018 Sullivan Beck

This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

=cut
