Refactor each() to foreach() for compatibility with PHP 7.2

[drbyte]

An RFC for PHP 7.2 has been voted on for inclusion in PHP 7.2. It proposes to deprecate the each() function for PHP 7.2 and removes it in 8.0.

The each() function is exponentially slower and wastes resources vs foreach(), so we're refactoring it now whether PHP 7.2 finally does adopt it or not.

Things to note when refactoring:

1. foreach() doesn't need a reset() to be called before it runs, so those can be removed.
2. There are 3 syntax formats, depending on how the parameters are presented in the list() call:

a) while(list($key, $value) = each($foo))
This becomes foreach($foo as $key => $value)

b) while(list(, $value) = each($foo))
This becomes foreach($foo as $value)

c) while(list($key, ) = each($foo))
This becomes foreach($foo as $key => $value)

[zcwilt]

👍

[ajeh]

👍

[drbyte]

Note: our various imported vendor packages we leverage will require updates; will cross that bridge when they push new versions.

[dakanji]

@drbyte, How would you suggest tackling instances where there is no while loop involved?

Examples:
a) list($key, $value) = each($foo)

b) list(, $value) = each($foo)

c) list($key, ) = each($foo)

[drbyte]

I'm not aware of any such use cases in actual Zen Cart code, old or new.

Reading http://php.net/manual/en/function.each.php and http://php.net/manual/en/function.list.php offer some insight, particularly the fact that each only handles numeric indices, not named indices. I suspect you'll end up just referring to $foo[0] and $foo[1] etc, or some variation of that.

[dakanji]

Thanks. Came across these elsewhere and was looking for correct solutions when I found your post here.

For the record,

a) list($key, $value) = each($foo) is equivalent to:
$key = array_keys($foo)[0];
$value = array_values($foo)[0];


b) list(, $value) = each($foo) is equivalent to:
$value = array_values($foo)[0];

c) list($key, ) = each($foo) is equivalent to:
$key = array_keys($foo)[0];

... and list($key) = each($foo) is equivalent to Example C

[drbyte]

Agreed. Thanks for posting these.

It's unfortunate there's no shorter and equally expressive version as each() when used outside a loop.

[torvista]

I'm using php7.2 for development, PHPstorm marks "each" as deprecated.
My production site/hosting is already on 7.1.7.
Given the widespread use of "each" in 1.55 (>200 instances), and 7.2 due in November, what is the plan?

[drbyte]

We were discussing that earlier this week. We'll be tagging a new release.