NAME

Encode::Alias - alias definitions to encodings

SYNOPSIS

  use Encode;
  use Encode::Alias;
  define_alias( newName => ENCODING);

DESCRIPTION

Allows newName to be used as an alias for ENCODING. ENCODING may be either the name of an encoding or an encoding object (as described in Encode).

Currently newName can be specified in the following ways:

As a simple string.

As a qr// compiled regular expression, e.g.:

  define_alias( qr/^iso8859-(\d+)$/i => '"iso-8859-$1"' );

In this case if ENCODING is not a reference it is eval-ed to allow $1 etc. to be substituted. The example is one way to alias names as used in X11 fonts to the MIME names for the iso-8859-* family. Note the double quote inside the single quote.

If you are using a regex here, you have to use the quotes as shown or it won't work. Also note that regex handling is tricky even for the experienced. Use it with caution.

As a code reference, e.g.:

  define_alias( sub { return /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } , '');

In this case $_ will be set to the name that is being looked up and ENCODING is passed to the sub as its first argument. The example is another way to alias names as used in X11 fonts to the MIME names for the iso-8859-* family.

Alias overloading

You can override predefined aliases by simply applying define_alias(). New alias is always evaluated first and when neccessary define_alias() flushes internal cache to make new definition available.

  # redirect  SHIFT_JIS to MS/IBM Code Page 932, which is a
  # superset of SHIFT_JIS

  define_alias( qr/shift.*jis$/i  => '"cp932"' );
  define_alias( qr/sjis$/i        => '"cp932"' );

If you want to zap all predefined aliases, you can

  Encode::Alias->undef_aliases;

to do so. And

  Encode::Alias->init_aliases;

gets factory setting back.

SEE ALSO

Encode, Encode::Supported