/**
* recursivley expands a flattened array into a heirarchy of arrays
* based on a key separator
* @param mixed $iterable
* @return array returns the same array
*/
function expand($iterable, $separator = '.')
{
$array = [];
$keys_to_recurse = [];
foreach ($iterable as $key => $value) {
$sep_position = strpos($key, $separator);
if ($sep_position === false) {
$array[$key] = $value;
/* copy over the value verbatim */
continue;
}
$prefix = substr($key, 0, $sep_position);
$suffix = substr($key, $sep_position + 1);
if (!array_key_exists($prefix, $array)) {
$array[$prefix] = [];
$keys_to_recurse[] = $prefix;
}
$array[$prefix][$suffix] = $value;
}
foreach ($keys_to_recurse as $key) {
$array[$key] = array_expand($array[$key], $separator);
}
return $array;
}
public function test_array_expand()
{
$array = array_expand(['foo.bar' => 'baz']);
$this->assertEquals(['foo' => ['bar' => 'baz']], $array);
}
