Template as array key

[Baptouuuu]

Is there a way to use a template to specify a key of an array like so : https://psalm.dev/r/7469115e9c ?

toArray('i', 1) => array{i: int}

[orklah]

You can have something similar like: https://psalm.dev/r/24318db73e but it seems Psalm choke on templates in offsets for a shape: https://psalm.dev/r/c1eafbc924. It considers K as an offset, which is weird

[AndrolGenhald]

Hadn't considered this use case before, but I've always done array-shapes as array{somekey: int} rather than array{"somekey": int}, probably because it's familiar from JavaScript and TypeScript. It would be nice to support templates here, but it would be a breaking change, and I'm not sure exactly how non-literal-string templates would work, I'd think maybe we'd want it to only consider templates that are of literal-string, since otherwise the array shape isn't possible anyway.

[Baptouuuu]

Indeed it should be literal-string

For a bit of context for why I want to do this: I'm trying to build objects to define an OpenAPI schema that can be used to validate a request and that returns an array shape of the payload (my goal is to define my types once instead of duplicating them between OpenAPI and manually specifying the array shape in my controllers). So I need the types to compose and using array<K, V> as suggested (even though it works for the simple case above) is not of much help.

Do you know if it would be complicated to implement this ?

[AndrolGenhald]

I opened #7906.

I'm not sure exactly how this would work for many keys, are you planning to do something like $array += toArray($key, $value) for each key? If you have a bunch of keys and values I think a simpler solution might be to improve array_combine to return array shapes when both arguments are array shapes (something I've wanted for some of my own code as well).

[Baptouuuu]

No I only need to define one key at a time and then use intersections. For example array_merge(toArray('foo', 42), toArray('bar', '*'))

[AndrolGenhald]

It looks like both addition and array_merge work to combine array shapes, so all we need to do then is implement template keys.