How to know if a change will be made or was made?

[codingedgar]

I see two options:

1. Maybe the update functions can tell if a change was performed.
2. Maybe the guards can be exported functions that state if a change was performed or not.

1 Cons

• The update functions have to return a tuple?

2 Cons

• The guards shouldn't be too underperforming to avoid the overhead of running them twice.
• The guards will be run twice.

1 Pros

• The guards can still be functions.
• The guards will only be run once.

2 Pros

• The user can check if the function will or not perform an action without running the action itself, opening other kinds of branching.

Update:
I think I like option 1, with option 2.

• Extract and export guards as functions
• Make updates functions return if they performed a change or not

[codingedgar]

Maybe nothing is needed, might no be very performant but using deep equals on the user's side might be enough? Guards as functions are still very nice I think, but maybe option 1 is unnecessary.