Speaking briefly, Unicode is the way of the
future, and even many modern systems have strong
support for it. Perl 6 is a language of the
future plus present, not of the past, and
shouldn't be limited by things that are only
issues for older systems while even then being
easy to work-around on them.
I say that we should exploit all the Unicode
characters reasonably possible to make for a more
elegant language, and any tools currently behind
will catch up before long.
In this case, I support the use of any
international currency symbol for use as Perl
sigils and/or operators as appropriate. Eg, we
already use $ (dollar; unicode=0024; utf8=24) and
¥ (yen; unicode=00A5; utf8=C2A5), and I suggest
that the next best one to exploit is ¤ (euro;
unicode=20AC; utf8=E282AC), and the next best is
£ (pound; unicode=00A3; utf8=C2A3). In my
experience, the ¢ (cent; unicode=00A3; utf8=C2A3)
is no harder to type than either of those.
In some cases, typing a ¢ is easier than most of
those characters. On a Macintosh keyboard,
typing opt-4 will get a ¢ as shift-4 gets a $.
For that matter, Macintosh keyboards and their
'option' key allows one to type twice as many
characters without entering special codes or
using an input palette as other keyboards having
only a 'shift' key do. So in that respect, if
you want a sigil that is meant to be discouraged
due to being harder to type, then ¢ may be a
worse choice than some other options.
On the other hand, if you want to use the ¢ due
to its being conceptually tied to $, that they
are different units of currency meant to be used
together, then the ¢ is fine.
All this being said, if you explicitly want to
have ASCII alternatives for all Unicode
characters being used, then I suggest it is best
to keep the use of Unicode characters mainly in
operators, because those are always surrounded by
whitespace and can easily be substituted for
latin words.
Whereas, because sigils are always right next to
ordinary word characters, I suggest that they
should always be ASCII characters, or that the
ASCII equivalent should not contain any word
characters. My impression is that sigils
containing alphanumerics just look wrong.
Perhaps a solution here for an ASCII equivalent
is something combining the $ and something else.
How about this twigil, which combines '::' and
'$':
:$:
Does that conflict with anything?
-- Darren Duncan