/**
* Check if all types are the same, in which case just return that type.
* Otherwise, create the UnionType and return.
* Also automatically flatten all nested UnionTypes.
*
* @param Type $type Require at least one type
* @param Type|Type[] ...$types
*
* @return UnionType|Type
*/
public static function createIfNotDuplicate(Type $type, Type ...$types)
{
$types = array_merge([$type], $types);
// Flatten nested UnionTypes
$types = Type::flatten($types);
if (array_any($types, function (Type $type, $key, array $collection) {
return $type instanceof UnionType;
})) {
throw new \LogicException("UnionType::flatten() failed to flatten nested UnionTypes.");
}
$types = Type::unique($types);
if (count($types) <= 1) {
return first($types);
}
return new UnionType(array_shift($types), $types);
}
/**
* Flatten Types, e.g. flatten UnionTypes.
*
* This function won't have much of an effect on most types, unless they contain subtypes.
*
* Because this function preserves duplicate entries, usually it may be preferable to use Type::unique()
* which also flattens and removes duplicate entries.
*
* @param Type|Type[] ...$types Use array dereferencing to pass an array into this function.
*
* @return array
*/
public static function flatten(Type ...$types)
{
// Flatten types with subtypes e.g. UnionTypes
$walker = function (Type $x) {
// If the types $x contains is not just itself, go deeper!
if (count($x->getTypes()) !== 1 or !first($x->getTypes())->typeof($x)) {
return Type::flatten($x);
}
return $x->getTypes();
};
$x = array_map($walker, $types);
return array_flatten($x);
}
