Should createComputed return a Computed? Or should ReadSignal be implemented slightly differently?

[manuel-plavsic]

I think that the current state of createComputed is not ideal, since it might be slightly unclear how ReadSignal (the type returned by createComputed) works under the hood.

In the following example,

// creating a computed
final derived = createComputed(
  // ...
);

// ...

// using the previously created computed
derived.previousValue;

If someone right clicks on derived.previousValue, the IDE will bring them to ReadSignal's previousValue, i.e.:

@override
T? get previousValue {
  // no-op
  return null;
}

which will not apply since it is explicitly overridden in the Computed class. The same applies for other ReadSignal members.

I propose either:

• returning Computed instead of ReadSingal (with some potential changes to Computed)
• changing ReadSignal internals so that it no longer contains a final T _value, but it contains a private setter that can update _value and previousValue. This way, the code for previousValue, hasPreviousValue and other affected members could be reused in Signal, Computed, ... and when the user control clicks on these members the code displayed will be valid in case of a Computed.

Do you like one of these 2 ideas?

[nank1ro]

I understand that this may be an inconvenience that the IDE brings to ReadSignal.
Is correct that createComputed returns a ReadSignal since the value depends on other signals and the user should not be able to manually change the value.

The logic is a bit chaotic, which is why the new reactive system is released as a dev version.

I will try to review the logic to see if it can be improved, also to make it work properly with the IDE.
I will check if the second solution you proposed is feasible

[nank1ro]

Hi @manuel-plavsic can you check and try #45?
I did all the fixes and now seems working as expected. I also simplified the logic so it should work fine also with the IDE.

[manuel-plavsic]

I really like the new logic! It is so much more intuitive. Thanks!