Online PHP editor | perf for sY2oD

<?php namespace Acme { class Collection { private $_items; public function __construct(array $items = [])/*: void*/ { $this->_items = $items; } public function filter(callable $callback): self { foreach ($this->_items as $key => $value) { if (!call_user_func($callback, $value)) { unset($this->_items[$key]); } } return $this; } public function map(callable $callback): self { foreach ($this->_items as $key => $value) { $this->_items[$key] = call_user_func($callback, $key, $value); } return $this; } public function reindex(): self { $this->_items = array_values($this->_items); } public function sprintf(string $format): self { return $this->map(function ($key, $value) use ($format) { return substr_count($format, '%s') === 1 ? sprintf($format, $value) : sprintf($format, $key, $value); }); } public function implode(string $delimiter = ''): string { $output = ''; $first = TRUE; foreach ($this->_items as $value) { if ($first) { $output .= $value; $first = FALSE; } else { $output .= "$delimiter$value"; } } return $output; } public static function property(string $property): callable { return function ($key, $value) use ($name) { return $value->$property; }; } } } namespace { use Acme\Collection; echo (new Collection([ 'one', 'two', (object)['foo' => 'FOO', 'bar' => 'BAR', 'baz' => 'BAZ'], 'three', (object)['bar' => 'BAR', 'qux' => 'QUX'], ])) ->filter('is_object') ->map(Collection::property('bar')) ->reindex() ->sprintf('(%s,%s)') ->implode('_');

Version	System time (s)	User time (s)	Memory (MiB)
7.0.1	0.007	0.043	20.16
7.0.0	0.003	0.043	20.10
5.6.16	0.010	0.053	20.54
5.6.15	0.007	0.073	18.14
5.6.14	0.010	0.080	18.12
5.6.13	0.000	0.043	18.14
5.6.12	0.017	0.073	21.13
5.6.11	0.003	0.043	21.00
5.6.10	0.017	0.077	21.00
5.6.9	0.003	0.080	21.08
5.6.8	0.010	0.037	20.37
5.5.30	0.003	0.083	17.98
5.5.29	0.000	0.097	17.96
5.5.28	0.003	0.060	20.78
5.5.27	0.017	0.077	20.73
5.5.26	0.017	0.073	20.68
5.5.25	0.010	0.033	20.67
5.5.24	0.013	0.070	20.20