Damian Conway wrote:
sub part ($classifier, *@list) {
....
return @parts;
}
Given the original example
(@foo,@bar,@zap) := part [ /foo/, /bar/, /zap/ ] @source;
this binds the contents of @parts to (@foo,@bar,@zap)? The
array refs in @parts are not flattened though. Is it correct
to think of flattening context as a lexical flattening? i.e.
only terms written with @ are flattened and the types of
the terms can be ignored?
BTW, if part were declared as an array method, the syntax
becomes
@source.part [ /foo/, /bar/, /zap/ ]
or
part @source: [ /foo/, /bar/, /zap/ ]
Can part be a multi-method defined in the array class
so the original example syntax can be used? (I'd prefer
the code too because the switch statement is eliminated.)
sub convert_to_sub ($classifier is topic) is cached {
Very nice.
for @classifiers.kv -> $index, &test {
An array::kv method? Very useful for sparse arrays, but
is this preferred for all arrays? An explicit index counter
seems simpler in this case.
my @indices = map { defined .key()($nextval) ?? .value
:: () } %classifiers;
That map body looks like a syntax error, but it isn't. Can I add
extra syntax like
map { defined(.key.($nextval)) ?? .value :: () }
to emphasize the fact that .key is returning a code ref?
Last, but not least, the Hash case returns a junction (most
likely of a single value). Junctions don't collapse like
superpositions, so I'm wondering what really happens.
Can you describe the evaluation? I'm really interested in how
long the junction lasts (how quickly it turns into an integer
index), and what happens with a duplicate (ambiguous?) index.
Sorry for so many questions. The code you wrote was just a
really, really good example of many Perl 6 features coming
together.
[This is out of order; Damian wrote it in another message.]
> Everything doesn't. Everything shouldn't be. Just the really common,
> important stuff.
So CGI.pm is in?
I don't think "really common, important" is a good criteria for
being in the core. IMHO it should be "language defining, awkward or
impossible to implement as a module".
Perhaps the part method can be implemented as a mix-in module that
extends array without subclassing it? AUTOLOAD can do that now
for packages. Are classes sealed or will they use AUTOLOAD too?
- Ken
