Does ForwardDiff need to be a dependency?

[rafaqz]

Requires.jl could be used to remove this... I'm not sure its for commonly used functions anyway

[jverzani]

Is there an issue with the dependency? It is heavy for the amount of use it gets here, so could possibly be removed in favor of some documentation.

[rafaqz]

It pulls in quite a few packages and slows load time and CI. when Roots.jl is otherwise very lean!

I was watching my travis build and realised how much of the stack was pulled in by that one dependency. Forward diff requires:

Compat 0.47.0
StaticArrays 0.5.0
DiffResults 0.0.1
DiffRules 0.0.4
NaNMath 0.2.2
SpecialFunctions 0.1.0
CommonSubexpressions 0.1.0

Thats half of the deps for one of my packages, and I don't use the functionality at all.

If you use a @require block you can keep Newton etc with ForwardDiff deps, they will just be exposed when ForwardDiff is actually loaded.

[rafaqz]

I'll put together a pull request if that helps

[jverzani]

I’d say better to remove and document how forwarddiff can be used. I can do that. If no one says whoa, give me a week.

…

On Wed, Jun 20, 2018 at 10:07 AM Rafael Schouten ***@***.***> wrote: I'll put together a pull request if that helps — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#112 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAZvTCotzisv5tIa47zm07wQJn8ixlqXks5t-lcagaJpZM4UuqI9> .

[rafaqz]

Ok if that's a better option. Another option is Roots that need a jacobian (or whatever it is) could be in another package.

[KristofferC]

Please not another package.

[ararslan]

Also please don't introduce a dependency on Requires.

[rafaqz]

Just out of curiosity what wrong with a dep on Requires? I've started using requires to remove other deps, thinking that was an ok option?

[ararslan]

It's a hack that's not really sound when it comes to precompilation. Better to wait until the language has first-class support for optional dependencies.

[rafaqz]

Thanks that is good to know. Optional deps will solve a lot of problems.

[rafaqz]

Requires seems to be a reliable solution for this kind of thing now: JuliaPackaging/Requires.jl#46

[jverzani]

That's good to know. I still think it best to remove ForwardDiff and document (though I really want this for my private pedagogical issues, but it does seem too heavy to pull in during testing). This is next on my todo list for this package.