Add set_if_not_equals_and to ActiveValue

[PacificBird]

PR Info

I did not start a separate issue for this change since I knew it would be easy enough to quickly implement myself. It fixes an issue I'm running into at work where I have a "base" ActiveModel created from one stream of data (in my case, weather data from a virtual provider, which are essentially just estimates) needs to be merged with an ActiveModel created from a second stream (in my case, weather data from a physical station that is more accurate but also drops data much more often). The ActiveValues I'm working with wrap an Option<T>. The "base" ActiveModel value is always set, acting as a sort of fall-back, and I want to replace it's values with those from the new ActiveModel only if those new values are Some. Currently, this has to be done using if let blocks, which gets really verbose when doing this patching over and over again. This PR makes it a lot more ergonomic, introducing ActiveValue::set_if_not_equals_and, as a sort of mixed analog of Option::is_some_and and Option::map_or. It works like this:

record.temperature.set_if_not_equals_and(raw.temperature.take().flatten(), Option::is_some);

instead of

if let ActiveValue::Set(Some(_)) = raw.temperature {
     record.temperature.set_if_not_equals(raw.temperature.take().flatten());
}

which saves an immense amount of visual noise when doing this operation repeatedly. I imagine it has many other use cases other than the one I made it for, and in any case this change brings the sea-orm more into alignment with the APIs available on the wrapper enums from the standard library.

Breaking Changes

No breaking changes to existing APIs, only additions.

Changes

Addition of pub fn set_if_not_equals_and(&mut self, value: V, f: impl FnOnce(&V) -> bool) to ActiveValue

[tyt2y3]

I like this, I am still thinking is there a better name for set_if_not_equals_and?

[PacificBird]

I like this, I am still thinking is there a better name for set_if_not_equals_and?

It is a pretty long method name, but to be consistent with both itself (this is just a specialization of the existing set_if_not_equals), and the standard library (is_some_and, is_ok_and, etc.) we're kinda shoehorned into this name. If the original method was just named set or something we could have set_if, but that ship has sailed.