✨ Add callable features and better error testing

[EssamWisam]

Closes #2 and #11

[ablaom]

Thanks @EssamWisam for this. I can review early next week.

[ablaom]

Callables do not need to be functions. You can make instances of any new struct a callable. Unless you need it for type dispatch, there is no need to annotate a type here.

[EssamWisam]

Done in 194c53e

[ablaom]

In Julia it is unfortunately difficult to recognise callability of an object (at least last time I researched this). So, reverse your logic here: if feature names is a vector of symbols then do X, otherwise do Y.

[ablaom]

Here's an example of a callable that is not a function:

struct Foo end
(::Foo)(x) = 2x

f = Foo()
f(4) # 8

f isa Function # false

[EssamWisam]

Done in 5e0af90

[ablaom]

Thanks for this. It's good to have this extra features.

Appreciate the detailed error catching cleanup. Makes it easier to tweak error messages in the future.

[ablaom]

Re 1.6 fail: Since 1.10 is the new LTS release, you can bump julia compat to 1.6 and in CI.yml change 1.6 to 1.10.

[EssamWisam]

Will get back to this soon just nearing a flight.

[EssamWisam]

Re 1.6 fail: Since 1.10 is the new LTS release, you can bump julia compat to 1.6 and in CI.yml change 1.6 to 1.10.

It doesn't sound quite intuitive to me 😊 (since the version numbers are different) but I did that.

[ablaom]

My bad. I meant bump compat to julia=1.10.

You also have some conflict to resolve.

[ablaom]

One final question. At the user interface point, can she specify features::Symbol instead of a vector (that you then wrap as a vector for downstream use)? We typically allow this in MLJ models.

[ablaom]

Ready to rock and roll 🎶

Thank you for this valuable contribution, @EssamWisam

[EssamWisam]

Thank you will merge now and consider any last PR needed before publishing package.