Linking $effect to the older subscribe() function in the documentation.

[peterhoward42]

Describe the problem

I did not realise that $effect can be used as a drop-in replacement where Svelte4 code that uses subscribe() to a store value - despite reading and revisiting the documentation several times.

This despite being now quite comfortable with $state runes and replacing most of my stores with them.

I suspect that many Svelte4 developers will be accustomed and comfortable with the idea and the terminology of "subscribe".

And is not $effect effectively an implicit subscriber? I have now found switching my subscribers to $effects is painless and produces clearer code.

Describe the proposed solution

I think that explaining in the documentation that $effect can be viewed as an implicit subscriber, and as being a good replacement for the older subscribe function will greatly speed up and ease people "getting" it.

I've made a similar suggestion suggesting the same pattern in this issue #14975

The pattern I'm advocating in both issues is to get people on the "right page" conceptually by leading the narrative with the problems that a feature solves, or example use cases, and only then explaining how the feature is a solution.

Importance

nice to have

[rChaoz]

And issue is that only works inside .svelte files - REPL, while .subscribe() can by used anywhere, and $effect() can be used in any .svelte.js file.