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Postings from December 2004
On Sat, 04 Dec 2004 08:59:24 -0700, David Green <plato@edmc.net> wrote:
> In article <198c87380412032209261dcb17@mail.gmail.com>,
> mddiep@gmail.com (Matt Diephouse) wrote:
> >Supposing
> > class Filehandle does Iterate; # Iterate or Iterator?
> >we have an easy way to create new iterators. I'm not sure how useful
> >they would be in Perl 6
>
> Maybe the class doesn't do it, but one of its methods does? Then you
> can call it whatever makes sense.
C<does Iterate> signifies a role named "Iterate". Roles are sort of a
mix of interfaces and mixins (as I understand it -- I'm still waiting
for E12). So saying a class fulfills a role just means that it
provides certain methods. In this case, I was saying class with the
Iterate role would provide a C<.next> method.
> >Which be even cuter like this (I think):
> > for iter($sth.execute) -> $results { ... }
> >where iter creates an Iterator object that just knows to call C<.next>
> >on its argument.
>
> That still seems too cumbersome to me. Isn't it "for" that knows to
> call .next (or .sequel, whatever)? I'm thinking that that is the
> point of "for $foo", which should be approximately the same as "while
> $foo.next". We've got "while" for looping, ".next" for iterating,
> and "for" for doing both in one convenient little shortcut.
But for needs to know if it has an iterator or a list. You don't want
it iterating over things you didn't want it iterating. In this case, I
was suggesting making an, though I suppose something like
C<$sth.execute> could just return one.
> >Hoping I haven't removed all doubt of my foolishness,
>
> I'm hoping this reply reassures you.
Thanks.
--
matt diephouse
http://matt.diephouse.com
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