in reply to How to convert hash keys to utf8

In the end, I wrote this:
use Data::Structure::Util qw(get_refs utf8_on); sub _perl_to_python_utf8_on { # We need to convert the hash keys ourselves. # 'get_refs' digs through the data structure # and returns an array ref of every reference # in the structure, at all levels. # All Hail CPAN; so glad I didn't have to walk # the data myself. my $refs = get_refs( $_[0] ); # For each ref, process just the hashes. for my $ref ( @{$refs} ) { if ( ref($ref) eq 'HASH' ) { for my $key ( keys %$ref ) { # See text below. $ref->{ utf8_on($key) } = $ref->{$key}; } } } # Let the utility convert everything else. return utf8_on( $_[0] ); }
You might think that the statement $ref->{ utf8_on($key) } = $ref->{$key}; would produce duplicate keys, but it does not; I went back and wrote key counting tests to prove it after reading other comments in this thread. The key (pun intended) to understanding what's going on here is that I believe utf8_on() only twiddles metadata; it does not change the actual value of the key. Hence we don't get duplicate entries and do not need to do
$ref->{ utf8_on($key) } = delete $ref->{$key}.
You'd also think that I've now mismatched the key string and its metadata, but Inline::Python seems to be Doing the Right Thing with it, so I am leaving well enough alone for now. Maybe the utf8 'value' of each char is the same as its ascii value when less than 128 or 255?