Michael Lazzaro <[EMAIL PROTECTED]> writes:
> On Wednesday, December 11, 2002, at 06:56 PM, Simon Cozens wrote:
> > [EMAIL PROTECTED] (Michael Lazzaro) writes:
> >> Welllll... yes and no. You can make the same argument for operators
> >> upon scalars, for example, since 'scalar' is arguably no more
> >> universal than 'array'. And we could easily use that argument to
> >> remove *all* builtins, period:
> >
> > Now you're getting the idea.
>
> Yes. But Java sucks. Me no like make Perl like Java.
>
> I would still like to be able to do things in Perl6 like:
>
> @out = sort map {...} grep { ... } @in; # [1]
>
> Even though that technically means having sort, map, grep as builtins.
>
> We can make that
>
> @out = @in.grep({...}).map({...}).sort; # [2]
>
> if we want to grind our OO axe, but I find that syntax disappointing.
> I like that the idea is important enough in Perl to have it's own
> grammar, but I realize the problem of namespace pollution involved in
> having a bunch of builtins called grep, map, whatever.
>
> The only encompassing solution would seem to be to find a grammar rule
> by which map,grep,etc are unambiguously methods of Array, but can
> still be called in a fashion similar to [1]. That would, I suspect,
> satisfy everyone.
What's wrong with:
class Array {
method grep ( &block ) {
foreach .values {
yield $_ if &block($_);
}
}
method grep ( Rule $rule ) {
foreach .values {
yield $_ if /$rule/;
}
}
...
}
sub grep (Object $obj, @*ary) { @ary.grep($obj); }
AFAICT, (modulo getting the laziness done right, this should allow
you to write)
grep { ... } @ary;
grep /.../, @ary;
Writing the
grep foo($_), @ary
form in Perl 6 is left as an exercise to the interested reader, I get
the feeling it's going to have to wait until you can write 'special
form' subs.
sub grep ( rx/<expr>/ $expr, @*ary ) {
grep $expr.as_block, @ary
}
Might be one approach, but I'm waiting for Larry.
