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Postings from October 2001
John asked:
> So, what about simple array accessors?
Writing:
class Demo;
my @.colors is public;
gives you:
> $obj.colors('red', 'green', 'blue');
No. $obj.colors() takes no arguments.
> $obj.colors = ('red', 'green', 'blue');
Yes.
> $obj.colors = ['red', 'green', 'blue' ];
Yes. Arrays and array refs are (generally) interconvertable in Perl 6.
> push $obj.colors, 'red', 'green', 'blue;
Yes.
> pop $obj.colors;
Yes.
> print $obj.colors[1]
Yes.
> @{$obj.colors}[1]??
Yes (though you're missing the rest of the ternary operator there ;-)
> $obj.colors->[1]?? ;)
No. But "yes" to the Perl 6 equivalent:
$obj.colors.[1]
> Can/will such an accessor be auto-created?
Yes.
> How about hashes
Yes:
class Demo;
my %.fruit is public;
> (or "pairs"?)
Pairs are just a scalar type:
class Demo;
my PAIR $.pear is public;
> $obj.fruit(apple => 'red', berry => 'blue');
No.
> $obj.fruit = (apple => 'red', berry => 'blue');
Yes.
> $obj.fruit = { apple => 'red', berry => 'blue' };
Yes. Hashes and hash refs are (generally) intraconvertable in Perl 6.
> # Change apple color, but leave the blue berry
> $obj.fruit(apple => 'green');
No. You want:
$obj.fruit{apple} = 'green';
> print $obj.fruit('apple'); # green
No. You want:
print $obj.fruit{apple};
> Regardless of whether something like the above two examples can/will be
> auto-created, what would those methods look like anyway? Would they simply
> be:
>
> method colors is lvalue { return @.colors }
> method fruit is lvalue { return %.fruit }
Close. They'd actually be:
method colors is lvalue () { return @.colors }
method fruit is lvalue () { return %.fruit }
I.e. explicitly take no arguments.
> How many of the examples with the code above support?
Most of them, evidently.
Damian
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