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Date: Tue, 25 May 2021 02:20:23 -0700
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Subject: A little syntactic sugar on array_* function calls?
From: karoly@negyesi.net (Karoly Negyesi)

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Hi,

I was wondering whether $array->map($somefunction) would be possible. I am
not a C programmer by any stretch but reading ZEND_VM_HOT_OBJ_HANDLER(112
it seems to me it should be quite easy (famous last words) to find out if
object is an array and if so then

1. prepend the string array_ before the method name
2. based on a small lookup table move the "object" to the right place --
either first argument or second.
3. do a function call instead of a method call.

Regarding #2 by default it's the first:

$array->flip() becomes array_flip($array)
$array->column($column_key, $index_key) becomes array_column($array,
$column_key, $index_key)
$array->merge($array2, $array3) becomes array_merge($array, $array2,
$array3)

There'd be a small list of methods/functions where it's the second, for
example:

$array->map($fn) becomes array_map($fn, $array)
$array->search($needle, $strict) becomes array_search($needle, $array,
$strict)
$array->key_exists($key) becomes array_key_exists($key, $array)

(Is there even any other?)

For phase 1 we could skip the functions which gets the first argument by
reference (walk, sort) and figure it out later. Hand waving yes but never
let perfect stand in the way of good enough :)

Look how nicely this reads:

$array->map($fn)->filter($fn2)

Compared to array_filter(array_map($fn, $array), $fn2)

I see no BC concerns here because in any previous PHP versions this is a
fatal error. I do not see any syntax ambiguity either but here I am
probably just naive. It could also be usable with user defined functions.

What do you think?

Karoly Negyesi

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