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Date: Fri, 28 Oct 2022 17:41:05 +0200
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To: tyson andre <tysonandre775@hotmail.com>,
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Subject: Re: [PHP-DEV] Proposal: Expanded iterable helper functions and
 aliasing iterator_to_array in `iterable\` namespace
From: tim@bastelstu.be (=?UTF-8?Q?Tim_D=c3=bcsterhus?=)

Hi

On 10/28/22 15:45, tyson andre wrote:
> - `iterable\count(...)` (alias of iterator_count)
> - `iterable\to_array(Traversable $iterator, bool $preserve_keys = true): array` (alias of iterator_to_array, so that users can stop using a misleading name)

I wonder if this should be made an alias or if the introduction of the 
namespace this is a good opportunity to revisit the `$preserve_keys = 
true` default choice. See also this email in the voting discussion for a 
previous iter*able*_to_array() RFC: 
https://externals.io/message/102562#102616

> - `iterable\any(iterable $input, ?callable $callback = null): bool` - Determines whether any value of the iterable satisfies the predicate.
>    and all() - Determines whether all values of the iterable satisfies the predicate.

I would not make the callable optional. If one really wants to filter on 
the falsyness of the items, `any($i, fn ($v) => !!$v)` is easy enough.

I'd likely also swap the order of parameters, having the callable first 
is more natural with a possible pipe operator or partial application.

It also is arguably more readable when using nested function calls, 
because the callback appears immediately beside the function name:

(Callback first)

iterable\count(
   iterable\filter(
     fn ($v) => $v > 5
     iterable\map(
       fn ($v) => strlen($v),
       $iterable
     )
   )
)

vs

(Callable last)

iterable\count(
   iterable\filter(
     iterable\map(
       $iterable,
       fn ($v) => strlen($v)
     ),
     fn ($v) => $v > 5
   )
)


> - `iterable\unique_values(iterable $iterable): array {}`
> 
>    Returns true if this iterable includes a value identical to $value (`===`).
> - `iterable\includes_value(iterable $iterable, mixed $value): bool {}`
>     Returns a list of unique values of $iterable

It appears you mixed up the descriptions here.

> Any comments?
> 

Your proposals look good to me. Especially `any` and `all` are something 
I'm missing somewhat regularly.

Is there a reason there is no `iterable\map()` and `iterable\filter()` 
(that I used in my example above)?

Best regards
Tim Düsterhus