forked from lstrojny/functional-php
-
Notifications
You must be signed in to change notification settings - Fork 0
/
CartesianProduct.php
62 lines (56 loc) · 1.9 KB
/
CartesianProduct.php
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
<?php
/**
* @package Functional-php
* @author Hugo Sales <hugo@hsal.es>
* @copyright 2021 Lars Strojny
* @license https://opensource.org/licenses/MIT MIT
* @link https://github.com/lstrojny/functional-php
*/
namespace Functional;
use Functional\Exceptions\InvalidArgumentException;
use Traversable;
/**
* @param string|array $separator
* @param array ...$collections
* @return array
* @no-named-arguments
*/
function cartesian_product($separator, ...$collections)
{
InvalidArgumentException::assertIntegerGreaterThanOrEqual(\count($collections), 2, __FUNCTION__, 2); // TODO not great
$aggregation = [];
$left = \array_shift($collections);
$index = 2;
InvalidArgumentException::assertCollection($left, __FUNCTION__, $index);
while (true) {
$right = \array_shift($collections);
InvalidArgumentException::assertCollection($right, __FUNCTION__, $index + 1);
$left_index = 0;
foreach ($left as $l) {
$right_index = 0;
foreach ($right as $r) {
InvalidArgumentException::assertStringable($l, __FUNCTION__, $index, $left_index);
InvalidArgumentException::assertStringable($r, __FUNCTION__, $index + 1, $right_index);
if (\is_string($separator)) {
$aggregation[] = "{$l}{$separator}{$r}";
} else if (\is_array($separator)) {
foreach ($separator as $sep) {
$aggregation[] = "{$l}{$sep}{$r}";
}
} else {
// TODO assert that $separator is string or array of strings
}
++$right_index;
}
++$left_index;
}
++$index;
if (empty($collections)) {
break;
} else {
$left = $aggregation;
$aggregation = [];
}
}
return $aggregation;
}