Parameterization with Package (ie. Distributions)

[lrennels]

This handles #754, originally pointed out on the forum at https://forum.mimiframework.org/t/set-a-parameter-as-a-distribution/106/15.

We need to handle the issue of parameterizing a Parameter or Distribution with a type from another package like Distributions, specifically something like this:

lws_distribution = Parameter{Distributions.Normal{Float64}}()

The error originally stems from like 271 of @defcomp:

datum_type = (datum_type === nothing ? Number : Main.eval(datum_type))

@davidanthoff suggests the following : "We can discuss the problem with Distributions on Fri. We might just have slightly rewrite the expression that gets passed to the Main.eval call, so that in the expression tree we don't use a symbol Distributions (which it will then try to resolve in the Main module, where Distributions isn't loaded), but instead just put a ref to the Distributions module itself into the AST that we pass to eval. I think it should then work without a name resolution."

[codecov]

Codecov Report

Merging #757 into master will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #757      +/-   ##
==========================================
+ Coverage   77.90%   77.91%   +0.01%     
==========================================
  Files          36       36              
  Lines        2996     2998       +2     
==========================================
+ Hits         2334     2336       +2     
  Misses        662      662              

Flag	Coverage Δ
#unittests	77.91% <100.00%> (+0.01%)	⬆️

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Impacted Files	Coverage Δ
src/core/defcomp.jl	83.90% <100.00%> (+0.18%)	⬆️

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[lrennels]

@davidanthoff the calls look like this:

@debug "before: datum type is $datum_type, which is of type $(typeof(datum_type))"
datum_type = (datum_type === nothing ? Number : Main.eval(datum_type))
@debug "after: datum type is $datum_type, which is of type $(typeof(datum_type))"

which returns

┌ Debug: before: datum type is Distributions.Normal{Float64}, which is of type Expr
└ @ Mimi ~/.julia/dev/Mimi/src/core/defcomp.jl:277
┌ Debug: after: datum type is Normal{Float64}, which is of type DataType
└ @ Mimi ~/.julia/dev/Mimi/src/core/defcomp.jl:279

I think that makes sense, since if you call Main.eval(Distributions.Normal{Float64}) without Distributions loaded you get an error. This means we're calling Main.eval within @defcomp, but I'm not quite sure what to do from here ... something with modules perhaps.

I also added a wip file with I think is what we want to work?

[lrennels]

@davidanthoff ok I think this works ...

[davidanthoff]

Looks good to me.