short array_push($a,...$b) syntax

[lunter2]

Description

Description:

$a[]=$b is equivalent to array_push($a,$b)
$a[]=...$b should be equivalent to array_push($a,...$b)

Test script:

<?php
 $a=[0];
 $a[]=...[1,2]; // array_push($a,...[1,2]);
 print_r($a);
?>

Expected result:

Array ( [0] => 0 [1] => 1 [2] => 2 )

Actual result:

Parse error: syntax error, unexpected '...' (T_ELLIPSIS) in C:\htdocs\wwwroot\fast_array_push.php on line 4

[iluuu1994]

This looks off to me personally. We already have various ways to achieve similar things, some with slightly different semantics ([...$a, ...$b], array_push($a, ...$b), array_merge($a, $b), $a + $b, etc), so I'm not sure if introducing more alternatives improves the situation.

Regardless of my own opinion, as this is a language change it would need to go through the RFC process.

[lunter2]

[...$a, ...$b] and array_merge($a, $b)
are very, very, very slow therefore they are not usable

<?php
 ini_set('memory_limit',-1);

 $i=10000;

 $a=[];
 $time_a=microtime(true);
 for($z=0;$z<$i;$z++){
  $a=array_merge($a,[0,1,2,3,4,5,6,7,8,9]);
 }
 $time_a=microtime(true)-$time_a;

 $b=[];
 $time_b=microtime(true);
 for($z=0;$z<$i;$z++){
  $b=[...$b,...[0,1,2,3,4,5,6,7,8,9]];
 }
 $time_b=microtime(true)-$time_b;

 $c=[];
 $time_c=microtime(true);
 for($z=0;$z<$i;$z++){
  array_push($c,...[0,1,2,3,4,5,6,7,8,9]); // $c[]=...[0,1,2,3,4,5,6,7,8,9];
 }
 $time_c=microtime(true)-$time_c;

 print($time_a.' sec');
 print('<br/>');
 print($time_b.' sec');
 print('<br/>');
 print($time_c.' sec');
?>

1.4468619823456 sec
2.5033910274506 sec
0.0012228488922119 sec WOW!!!!!!!!!!!!!!!!!!!!!!

[iluuu1994]

Yes, array_merge is slow here because the array keeps getting copied. This is an option though.

$as = [];
for ($z = 0; $z < $i; $z++) {
    $as[] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
}
$a = array_merge(...$as);

Or the array_push($a, ...$b);, as mentioned in your comment.

[mvorisek]

This issue should be closed in favor of #10791 (and reopened), array_merge/array_push will be always slower as discussed in #9881

[iluuu1994]

@mvorisek I mean, we've talked about this problem before. Generally I don't consider GitHub issues a good fit for feature requests. This is not the encouraged platform for discussions, many people participate in discussions but are just subscribed to the mailing list but don't subscribe all of php-src's PRs as they are noisy. Feature requests are often incomplete (e.g. in this example, what is the return value of $a[...] = $b;?) or have overlap with other feature requests. It also needs to be shown why the feature is necessary, i.e. why array_push($a, ...$b); is not enough in this case. Furthermore, feature requests that require RFCs usually just lay around with nobody taking initiative because they are time consuming. This mainly comes from the fact that the requester usually doesn't have C experience and so can't help with the implementation while the people who do have their own wishes and ideas.

We may consider using something like GitHub discussions in the future as it provides some things the mailing list does not. But that would likely require an RFC as well.

Given the reasoning above I'm closing this feature request. You may try the mailing list for some initial feedback. If it is received well the next step would be an RFC. Thank you for your interest in PHP!