/**
* Convert a traversable or other value into an array or leave it as is if it already is an array.
*
* Additional argument can be set to true to force conversion of empty values
* into empty arrays. By default any not-array and not-traversable value will
* be casted as array.
*
* @param mixed $var the value
* @param bool $empty_value_to_empty_array force conversion of empty values
* into empty arrays (optional, default is false)
* @return array the value as is if it is an array, or the value
* converted to an array
*/
function to_array($var, bool $empty_value_to_empty_array = false) : array
{
if ($empty_value_to_empty_array && empty($var)) {
return [];
}
if (is_array($var)) {
return $var;
}
if (is_traversable($var)) {
return traversable_map(pass_through, $var);
}
return (array) $var;
}
/**
* Flatten an array or a traversable.
*
* @param array|\Traversable $traversable the traversable to flatten
* @param bool $preserve_keys preserve original keys of all arrays (default is false)
* @return array flat array
*/
function traversable_flatten($traversable, bool $preserve_keys = false) : array
{
$flat = [];
if ($preserve_keys) {
foreach (to_traversable($traversable) as $key => $value) {
if (is_traversable($value)) {
$flat = array_merge($flat, traversable_flatten($value, true));
} else {
$flat[$key] = $value;
}
}
} else {
foreach (to_traversable($traversable) as $value) {
if (is_traversable($value)) {
foreach (traversable_flatten($value, false) as $subvalue) {
$flat[] = $subvalue;
}
} else {
$flat[] = $value;
}
}
}
return $flat;
}