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Reply-To: Levi Morrison <levi.morrison@datadoghq.com>
Date: Sun, 30 Aug 2020 20:08:05 -0600
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To: tyson andre <tysonandre775@hotmail.com>
Cc: PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Proposal: Adding functions any(iterable $input,
 ?callable $cb = null, int $use_flags=0) and all(...)
From: internals@lists.php.net ("Levi Morrison via internals")

I was actually working on this sort of thing recently. _Technically_,
you can support `all`, `any`, and `first` by using a single function:

    function find_first(iterable $of, callable($value, $key): bool
$thatSatistifes): Iterator

It converts the $iterable into an Iterator, then calls the callback
for each key/value pair until one returns true, and then always
returns the iterator at the current position.

1. This allows you to know both key and value when making a decision.
2. By returning an iterator the caller can get both key and value.
3. By returning an iterator it can handle both the empty case and not
found cases with $result->valid() === false.
4. By returning an iterator it might be useful for processing the
remainder of the list somehow.

I'm not sure that in practice it would be that friendly, but it's
worth pointing out for discussion at least.