Re: [RFC] Add is_list(mixed $value): bool to check for list-like arrays

> >> I actually like the idea of flags added to is_array() for >> this. >> >> Something like: >> >> is_array($value, ZERO_INDEXED | ASSOCIATIVE | INTEGER_INDEXED) >> >> I’m not suggesting these names; they’re for illustration only. > > I'm strongly opposed to adding any flags to is_array - keeping basic type checks simple > would help in learning/reading/remembering the language, > has a small impact on performance for calls that aren't unambiguously qualified > (especially if using both), and it makes it harder to see issues like > is_array(really_long_multiline_call(arg1, arg2, ZERO_INDEXED)) tl;dr: How often do we find ourselves needing to check if an array uses ordered integer keys?? Compared to just forcing the passing through array_values?? For my implementation it’s only there because I’m experimenting with separating the three main types (for me): PHP unordered mixed keys, string-only-unordered-keys, and int-only-ordered-base-0-keys. Under most circumstances I would strongly agree. With that said, I think requiring a certain arrangement of keys is a rare case; presumption being a solution would be in place if it wasn’t. Further, I think there are quite a few options to manipulate keys and we have 20+ years of linguistic baggage. Thought exercise I’m going through that would let userland opt-in to the complexity of further restricting the type-checkable PHP array with possible flags (just to continue the exercise): 1. PHP_STD_ARRAY: unordered map with keys that are strings, integers, or both - default...no BC, no additional learning curve except when users want to be more specific; all systems normal. 2. STRING_KEYS: all the keys are strings. 3. INT_KEYS: all the strings are integers. 4. ORDERED_ASC: keys are ordered from least to greatest (string or int). 5. ORDERED_DESC: keys are ordered from greatest to least. 4. INT_KEYS_BASE_ZERO: the first key is 0 (??) I might be missing some cases, but this would cover current PHP array; the ability for users to sort on keys, not values; and wouldn’t require additional function or named thing as PHP “array” can be any of those things and it’s more a matter of whether users want to be more restrictive and why. My use case for wanting this is pretty much to be more opinionated in my library and make a hard distinction between a base-0-int-ordered-array and an string-unordered-array. My PHP-like variant is actually call List, funny enough - with the ability to make it an array (array_values) or a dictionary (prepending int indexes with a letter to address dynamic casting). And, again, I’ve never had to run a check really - because if I need a “pure array” - I run array_values. I’m cautious about introducing a new name against a known type as abstract as PHP array - which can be just about any combination of key-value pair constructs. If introducing a new name, I would hope to introduce a new type as well - even if under the hood it’s using checks against the more generic PHP array. function hello(list $my_list_maybe) The hope isn’t that the flags become a permanent fixture but allow better visibility into what userland wants from arrays without adding to the SL and without users needing to change their current mental models - do a lot of us *want* to have this ability (verify the metadata on keys of an array)?? Or is it just a fringe group of pedantic experimenters like me?? :) Cheers, Josh