Clean up exports

[penelopeysm]

Turing.jl/src/Turing.jl

Lines 80 to 84 in 24d5556

	export @model, # modelling
	@varname,
	@submodel, # Deprecated
	to_submodel,
	DynamicPPL,

Turing re-exports the entire DynamicPPL module, as shown above. This means that any breaking change in DynamicPPL is also technically a breaking change in Turing.

However, we haven't really obeyed this at all: many breaking changes in DynamicPPL have been released as patch level bumps in Turing. This means that technically, a patch version of Turing could break any code that looks like

using Turing
Turing.DynamicPPL.foo(...)

where foo was something that was changed in a minor release of DynamicPPL.

'But, Penny, who would write such horrible code?' I hear you ask. Well, if nobody would do that, then there's no reason to re-export DynamicPPL ;)

[penelopeysm]

While we're at it, maybe we don't need to re-export everything from these packages (though I could see making an exception for Distributions.jl):

Turing.jl/src/Turing.jl

Line 7 in 24d5556

@reexport using Distributions, MCMCChains, Libtask, AbstractMCMC, Bijectors

And maybe we can re-export LinearAlgebra.I too.

[penelopeysm]

Finally, I think the export list should be sorted / organised by the origin package of each symbol being exported, so the DynamicPPL stuff should be grouped, etc. It kind of is already, but not totally.

That will make it easier for us to know when something requires a breaking release.

[mhauru]

Libtask I would think wouldn't need any re-exporting, it seems like an implementation detail to me. Maybe Bijectors likewise. We probably need something from AbstractMCMC and MCMCChains, but I, too, would like to be more selective.

[penelopeysm]

Closed by #2474 (Turing 0.37.0). Curious as to why GitHub didn't auto-close it? Oh well.