How can I get a list of encodings that Perl 6 understands?

Question

I see a hash with a short list of encodings in /src/core/Rakudo/Internals.pm, but I cannot get to it outside of this. The NORMALIZE_ENCODING method is the only one that uses it. Use what is not on this list and you get an exception.

So, how can I find out what really is before I try it, especially since some important encodings are missing?

 my $encodings := nqp::hash( # fast mapping for identicals 'utf8', 'utf8', 'utf16', 'utf16', 'utf32', 'utf32', 'ascii', 'ascii', 'iso-8859-1', 'iso-8859-1', 'windows-1252', 'windows-1252', # with dash 'utf-8', 'utf8', 'utf-16', 'utf16', 'utf-32', 'utf32', # according to http://de.wikipedia.org/wiki/ISO-8859-1 'iso_8859-1:1987', 'iso-8859-1', 'iso_8859-1', 'iso-8859-1', 'iso-ir-100', 'iso-8859-1', 'latin1', 'iso-8859-1', 'latin-1', 'iso-8859-1', 'csisolatin1', 'iso-8859-1', 'l1', 'iso-8859-1', 'ibm819', 'iso-8859-1', 'cp819', 'iso-8859-1', ); method NORMALIZE_ENCODING(Str:D \encoding) { my str $key = nqp::unbox_s(encoding); if nqp::existskey($encodings,$key) { nqp::atkey($encodings,$key) } else { my str $lc = nqp::lc($key); nqp::existskey($encodings,$lc) ?? nqp::atkey($encodings,$lc) !! nqp::lc($key) } }