Minimize the amount of initial imports

[alecandido]

Motivation: As soon as you install eko, you'll need to wait a while on first import. This is needed for the eko application, but unnecessary and completely counter-intuitive for the eko library.

At the moment importing eko means importing eko.runner, and also eko.output.

Then, as it makes sense, importing runner means importing everything (see dependency graph).

How to improve

From my point of view:

• there is no way to improve on eko.runner: it's quite intuitive that uses all (or almost all) of the library
• but I'd say that we should not wait on the compilation of all the anomalous dimensions and so on, if you only need interpolation or strong coupling (or even masses, basis rotation, ...)

In particular, having to wait every time you install anew it's already a bit unpleasant in yadism, but much more in banana or runcards.

In practice

I'd say we just need to:

• shuffle back run_dglap inside eko.runner
• at this point we can keep the main __init__.py just for the version (no need for a separate module)
• update related docs

[alecandido]

I believe we don't need this any longer, because of:

• mainly the numba rearrangement
• and the forthcoming runner-less structure (in which runner will be optional, and thus by default importing much less)

Can we close this? @giacomomagni @felixhekhorn

[giacomomagni]

okay, fine

[felixhekhorn]

Agreed