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Postings from November 2003
On Wed, Nov 19, 2003 at 12:49:21PM -0800, Larry Wall wrote:
> Sorry, I wasn't being very clear. It wouldn't be logically attached to
> the outside of the for, but to the inside of the "confer", or whatever:
>
> @foo = gather {
> for @a -> $x { pick $x if mumble($x) }
> DEFAULT { @results }
> }
So ... the only way to get Damians semantics ...
On Wed, Nov 19, 2003 at 08:01:40AM +1100, Damian Conway wrote:
> * vector control structures like C<loop>, C<while>, and C<for> in
> a list context return a list of the values of the last statement
> each iteration evaluated;
>
> * vector control structures like C<loop>, C<while>, and C<for> in
> a scalar context return an integer indicating the number of
> times their block was iterated.
... is to surround the control structure with a gather { ... } ??
It seems like "gather" or whatever should be some sort of modifier to
for/loop/while/until
@foo = for : gather @a -> $x { ... }
if for : gather @a -> $x { ... } < 3 { ... } # ick!
if : gather for : gather @a -> $x { ... } < 3 { ... } # ick!**2
for : gather @a -> $x { ... } or @results;
for : gather @a -> $x { ... } or do { ... }
Okay, so the syntax isn't great. I'm just brainstorming.
Having a gather block just feels wrong to me. It's weird to say that
control structure X only has a result when placed inside of a special
block. But maybe it *needs* to be weird.
> On the other hand, putting the default up front is clearer if the
> block is long. Could even be something like:
>
> @foo = gather is default(@results) {
> for @a -> $x { pick $x if mumble($x) }
> }
Hmm.
@foo = for :gather,default(@results) @a -> $x { ... }
-Scott
--
Jonathan Scott Duff
duff@lighthouse.tamucc.edu
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