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Date: Wed, 18 Jan 2023 15:06:42 +0000 (GMT)
To: "G. P. B." <george.banyard@gmail.com>
cc: PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] [RFC] Saner array_(sum|product)()
From: derick@php.net (Derick Rethans)

On Tue, 17 Jan 2023, G. P. B. wrote:

> I would like to start the discussion about the Saner 
> array_(sum|product)() RFC: 
> https://wiki.php.net/rfc/saner-array-sum-product
> 
> Currently, the array_sum() and array_product() behave differently than 
> their userland implementation as they ignore arrays and objects, and 
> cast the remaining types to int/float. This is in contrast with the 
> behaviour of arithmetic operators that throw TypeErrors on types and 
> values that are not interpretable as int/float.
> 
> This RFC aims to resolve this discrepancy.

I think I agree with the premise of this RFC, but I do think a few 
details are wrongly addressed.

First of all, a clarification why this produces int(4) would be useful:

	$input = [true, STDERR, new stdClass(), [], gmp_init(6)];
	$output = array_sum($input);

I had to look up that STDERR would cast to int(3) :-)

I don't understand why this would result in a warning and a return of 
int(50):

	$a = [10, 15.6, gmp_init(25)];
	var_dump(array_sum($a));

Why doesn't this return float(50.6) instead? I realise that the 
array_reduce variant (below) does the same, but it's not what I would 
expect:

	<?php
	$input = [10, 15.6, gmp_init(25)];
	$output = array_reduce($input, fn($carry, $value) => $carry + $value, 0);

I think the phrase "If traversing the array transforms the return value 
into an object, if that object is not numerically castable an E_WARNING 
is emitted and the initial return value is returned instead, which may 
change the return value if scalar values were present in the array. " 
should come with an example :-)


cheers,
Derick