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

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February 4, 2020 22:24 andreas@dqxtech.net (Andreas Hennings)
On Tue, 4 Feb 2020 at 22:19, Larry Garfield <larry@garfieldtech.com> wrote:

> On Tue, Feb 4, 2020, at 12:40 PM, Aimeos | Norbert Sendetzky wrote: > > Am 04.02.20 um 19:17 schrieb Rowan Tommins: > > > I think Larry's point was that the flexibility of PHP's array type > makes it > > > really hard to pin down whether a given object is "array-like" or not, > and > > > which attributes a particular function actually cares about. > > > > What else besides array access, counting and traversing is possible that > > may differ from classes that implement those interfaces? > > > > > A general "intersection type" system might be more useful, because > then you > > > could require the parts you specifically needed, such as > > > "traversable&ArrayAccess" or "traversable&countable". > > > > I think that's too complicated and we should make it as easy as possible > > for PHP developers. > > > > Also, there's already an RFC for intersection types but it was never > > adopted: https://wiki.php.net/rfc/intersection_types > > > Rowan is exactly right and said it better than I did. > > The point is that "I can count() it", "I can foreach() it" and "I can > bracket it" are three different things; in practice, a given function > likely only cares about one, maybe two of those at a time. Adding a type > for "an object that mimics all of the dumb things arrays do, but now passes > differently" doesn't strike me as useful; it strikes me as the sort of > thing I'd reject in a code review if someone tried to do it in user space. > > The problem with PHP arrays is that they're not arrays; they're a hash map > with poor safety, lame error semantics, and some cheats to make them kinda > sorta look like arrays if you don't look too carefully. In practice, they > create more bugs than they fix. >
There is one good thing about arrays: They are passed along by-value by default, which gives them similar qualities as an "immutable" object. If you pass an array to a function as a parameter which is not by-reference, you can expect the original array to remain unchanged. (Objects or referenced variables within that array can still be modified of course) A function parameter which allows an object OR an array loses this advantage. If I have the choice between \stdClass and array for "unstructured tree of data", I will always prefer the array. ~~ Andreas
> > --Larry Garfield > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php > >