Create a Set/Map signal wrappers

[Harpush]

When working with Set and Map you can't wrap it in a signal as they are mutable. You can however create an abstraction around it to emulate a signal Set/Map.

I will be happy to create a PR

[eneajaho]

It reminds me of this one https://x.com/Enea_Jahollari/status/1826278131675586608 😅

[Harpush]

@eneajaho so what do you think? Should I work on that? Does it sound like a good addition?

[eneajaho]

what about reactive arrays?
This is a wide topic which comes to the part of -> should we do this? or should angular itself provide these?

[Harpush]

what about reactive arrays? This is a wide topic which comes to the part of -> should we do this? or should angular itself provide these?

I think arrays are different. There are known pattern how to use them immutably as they are serializable and state managements support them usually.
Set and Map are mutable by design and unlike arrays have no immutable patterns.

[Harpush]

@eneajaho The idea I have is:

export interface SetSignal<T> {
  (): ReadonlySet<T>
  readonly array: Signal<readonly T[]>
  readonly size: Signal<number>
  has(value: T): boolean
  add(values: T | T[]): void
  delete(values: T | T[]): void
  clear(): void
  replace(values: T[]): void
}

const valuesSet = createSetSignal([2, 3, 4, 4]); // SetSignal<number>

array, size and has are reactive while the others are not

I also think a good addition is allowing for the mirror technique here:

const values = signal([1,3,3]);
const valuesSet = createSetSignal(values); // SetSignal<number>
console.log(valuesSet.array()); // [1,3]
values.set([1,2,1]);
console.log(valuesSet.array()); // [1,2]

The biggest benefit here is that Set is much better than Record<string, true> in terms of performance

What do you think?