> > meth foo {
> > $_.meth; # defaults to the invocant
> > .meth; # operates on $_ which defaults to the invocant
> > $^.meth; # is the invocant
> > $^1.meth; # is the first invocant
> > $^2.meth; # is the second invocant
>
> I'm starting to get confused at the "need" for all these special
> variables. I vote that we steal from prior art in numerous other
> languages and just auto-set $SELF or $THIS or whatever and call it done.
The problem is that there is no globally safe name to use that uses letters
only. Also there is a certain line noise problem (which may not really be a
problem - but looks like one once we have a more concise alternative):
method foo {
$SELF.prop = $SELF.meth($SELF.get_foo, $SELF.get_bar);
$SELF.say("Hello " ~ $SELF.prop);
}
That looks considerably more messy than:
method foo {
$.prop = .meth(.get_foo, .get_bar);
.say("Hello " ~ $.prop);
}
Perl syntax is wonderful for being able to say as much as possible without
losing meaning - assuming you can read perl. The short identifiers are able
to express a lot in a little space.
> Having .method assume $SELF is an added nicety, but if it introduces
> added parsing problems then it's hardly worth it.
The .method problem isn't about parsing - it is about knowing which variable
it applies to.
Current syntax would do:
method foo ($self:) {
return grep { $self.is_ok( .value ) } $self.info_pairs;
# .value called on the topic $_
}
Proposed syntax previous to this thread
method foo {
return grep { .is_ok( $_.value ) } .info_pairs;
# .is_ok called on invocant not the topic
}
Proposed syntax in this thread (among various others)
method foo {
return grep { $^.is_ok( .value ) } $^.info_pairs;
# .value called on the topic
}
The goal is to be able to be concise yet intuitive - so that you could do:
my @good_objects = grep { .is_ok } @candidate_objects;
> OR, choose $^ and don't set $SELF (or $?SELF or whatever), but having
> dup short and long names is a waste, since people will always chose the
> short one (who uses English in Perl 5, really?)
That is the goal - to find some nice variable that looks vaguely usable and
that people won't rebel against using.
Paul
