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|
<?php
namespace ipl\Stdlib;
use Generator;
use InvalidArgumentException;
use IteratorIterator;
use Traversable;
use stdClass;
/**
* Detect and return the PHP type of the given subject
*
* If subject is an object, the name of the object's class is returned, otherwise the subject's type.
*
* @param mixed $subject
*
* @return string
*/
function get_php_type($subject)
{
if (is_object($subject)) {
return get_class($subject);
} else {
return gettype($subject);
}
}
/**
* Get the array value of the given subject
*
* @param array<mixed>|object|Traversable $subject
*
* @return array<mixed>
*
* @throws InvalidArgumentException If subject type is invalid
*/
function arrayval($subject)
{
if (is_array($subject)) {
return $subject;
}
if ($subject instanceof stdClass) {
return (array) $subject;
}
if ($subject instanceof Traversable) {
// Works for generators too
return iterator_to_array($subject);
}
throw new InvalidArgumentException(sprintf(
'arrayval expects arrays, objects or instances of Traversable. Got %s instead.',
get_php_type($subject)
));
}
/**
* Get the first key of an iterable
*
* @param iterable<mixed> $iterable
*
* @return mixed The first key of the iterable if it is not empty, null otherwise
*/
function iterable_key_first($iterable)
{
foreach ($iterable as $key => $_) {
return $key;
}
return null;
}
/**
* Get the first value of an iterable
*
* @param iterable<mixed> $iterable
*
* @return ?mixed
*/
function iterable_value_first($iterable)
{
foreach ($iterable as $_ => $value) {
return $value;
}
return null;
}
/**
* Yield sets of items from a sorted traversable grouped by a specific criterion gathered from a callback
*
* The traversable must be sorted by the criterion. The callback must return at least the criterion,
* but can also return value and key in addition.
*
* @param Traversable<mixed, mixed> $traversable
* @param callable(mixed $value, mixed $key): array{0: mixed, 1?: mixed, 2?: mixed} $groupBy
*
* @return Generator
*/
function yield_groups(Traversable $traversable, callable $groupBy): Generator
{
$iterator = new IteratorIterator($traversable);
$iterator->rewind();
if (! $iterator->valid()) {
return;
}
list($criterion, $v, $k) = array_pad((array) $groupBy($iterator->current(), $iterator->key()), 3, null);
$group = [$k ?? $iterator->key() => $v ?? $iterator->current()];
$iterator->next();
for (; $iterator->valid(); $iterator->next()) {
list($c, $v, $k) = array_pad((array) $groupBy($iterator->current(), $iterator->key()), 3, null);
if ($c !== $criterion) {
yield $criterion => $group;
$group = [];
$criterion = $c;
}
$group[$k ?? $iterator->key()] = $v ?? $iterator->current();
}
yield $criterion => $group;
}
|
