Re: [PHP-DEV] [RFC] "arrayable" pseudo type hint

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November 25, 2019 17:33 andreas@dqxtech.net (Andreas Hennings)
On Sun, 24 Nov 2019 at 16:55, CHU Zhaowei <me@jhdxr.com> wrote:

> > This proposal is not obsolete by the implementation of union types (i.e. > > array|Traversable) because union data types are types/interfaces > > combined by OR. "arrayable" is a combination of OR and AND: > > > > array|ArrayAccess&Countable&Traversable > > True. But it's also easy to implement in userland. Just create a new > interface that extends these three interfaces, then union types can work. > > ```php > interface Arrayable extends ArrayAccess, Countable, Traversable {} > > function array_x (array|Arrayable $arr) {} > ``` > > This is not something that userland cannot implement or very difficult to > implement. IMO it will make php more complex if we include this in the > core. Actually what you suggested has been totally covered by the future > scopes of the union types RFC.
or "intersection types": https://wiki.php.net/rfc/intersection_types
> If you really want to explore this idea, I think they are worth more > attention, instead of this specific case. > > Regards, > CHU Zhaowei > > > -----Original Message----- > > From: Aimeos | Norbert Sendetzky <norbert@aimeos.com> > > Sent: Wednesday, November 20, 2019 6:21 AM > > To: internals@lists.php.net > > Subject: [PHP-DEV] [RFC] "arrayable" pseudo type hint > > > > Since PHP 7.1, there's the "iterable" pseudo type hint that matches > "array" or > > "Traversable". > > > > PHP frameworks would profit from support of an "arrayable" pseudo type > hint > > that matches "array" and all objects that can be used like arrays. > > > > For that, "arrayable" objects have to implement these interfaces: > > - ArrayAccess > > - Countable > > - Traversable (i.e. either Iterator or IteratorAggregate) > > > > > > Implementing "arrayable" pseudo type, we could pass arrays or all > objects that > > can be used like arrays to methods and do: > > > > function useArrayable( arrayable $arg ) : arrayable { > > $cnt = count( $arg ); > > $value = $arg['key']; > > foreach( $arg as $key => $entry ); > > return $arg; > > } > > > > > > Best use cases are: > > > > - Laravel Collection > > ( > https://github.com/laravel/framework/blob/6.x/src/Illuminate/Support/Collect > > ion.php) > > > > - Aimeos Map (https://github.com/aimeos/map) > > > > > > No new interface is proposed because we can check if objects implement: > > > > ArrayAccess && Countable && Traversable > > > > > > Because "array" !== "arrayable", "arrayable objects will not be accepted > by > > array_* functions and all functions that only use "array" as type hint > for > > parameters and return types. > > > > > > This proposal is not obsolete by the implementation of union types (i.e. > > array|Traversable) because union data types are types/interfaces > > combined by OR. "arrayable" is a combination of OR and AND: > > > > array|ArrayAccess&Countable&Traversable > > > > > > Also, "arrayable" won't supersede "iterable" because > > > > - "iterable" matches arrays, iterators and generators > > > > - "arrayable" matches arrays and objects that can be used like arrays > > > > > > "Can be used like arrays" doesn't include support for empty() because it > works > > for empty arrays but not for "arrayable" objects without elements. > > If possible and requested, this may be addressed by another RFC. > > > > > > As Larry Garfield suggested, this pre-RFC proposes concentrates on the > > "arrayable" pseudo type only. > > > > It does NOT discusses that: > > > > - arrayable objects can be converted to arrays (Steven Wade works on an > RFC > > for a __toArray() magic function) > > > > - ArrayObject or any other arrayable object makes the array_* functions > less > > relevant in the future > > > > - arrayable objects can be passed to array_* functions in the future > > > > -- > > PHP Internals - PHP Runtime Development Mailing List To unsubscribe, > visit: > > http://www.php.net/unsub.php > > > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php > >