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To: Larry Garfield <larry@garfieldtech.com>, internals@lists.php.net
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Date: Tue, 19 Mar 2019 17:35:32 -0700
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Subject: Re: [PHP-DEV] RFC Draft: Comprehensions
From: smalyshev@gmail.com (Stanislav Malyshev)

Hi!

> Honestly, I cannot think of any case where I'd use a comprehension
> where I would definitely want an array and not a generator.  In the
> majority case both work equally well, cool, but I don't know when I
> would even use an array-dependent version.

They wouldn't work equally well. Generator is only
sequentially-addressable, and array is random-addressable. And in PHP
people do a lot of random addressing of arrays. Also, many functions
which accept arrays (and array type) won't work with generators.

> And converting from a generator to an array is trivial; the other
> way, very not so much.

Well, doing everything not using this syntax is trivial - if the point
is not doing anything that is already trivial, then we don't need this
syntax, as iterating over an array/sequence and applying an operation to
it is already trivial in both array and generator contexts, it's a
two-liner function in most cases. If the point is to add syntax sugar
for most frequently used cases, then I claim that the most frequently
used case is definitely not the generator one. I don't think I ever used
the generator one in python (I use list one all the time), and I maybe
used analogous construct in PHP once or twice (and again I use array_map
and more complex syntax for array transformations all the time).

BTW, how it's not trivial to make generator from array?

function generate($array) { foreach($array as $k => $v) yield $k => $v; }

Is there something I'm missing here?
-- 
Stas Malyshev
smalyshev@gmail.com