Simplify Stacktraces by Hiding Possibly Unnecessary Type Parameters? #36517
Comments
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Maybe we can use the compact flag for this? |
JeffBezanson
added
the
display and printing
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I had a version at some point where I just saved the last stack trace in a variable that could be printed with something like |
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We've talked in the distant past about having an automatic variable like |
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Where it's been implemented, julia> A = rand(3, 5);
julia> v = view(A, 1:2, :);
julia> typeof(v)
SubArray{Float64,2,Array{Float64,2},Tuple{UnitRange{Int64},Base.Slice{Base.OneTo{Int64}}},false}
julia> summary(v) # this is thanks to `showarg`
"2×5 view(::Array{Float64,2}, 1:2, :) with eltype Float64"So what about something like |
Is there a way to omit type parameters? I think a lot of issues like #36026 are hitting great points, but they are missing the key issue with stack traces because they are focused too much on minimal examples. Let's take a look at a very common example seen in the wild. Here a user uses a package function that autodiffs an un-autodiffable ODE definition:
And the error? Let me post it so we can fully understand its glory:
It's absolutely fantastic that Julia gives you all of the information in the world, letting you know everything about the problem all of the way down because it's all implemented in Julia. But... it's daunting. For most people, this is only harmful because there's too much information clouding what's really the issue.
The Core Issue
I tried to put a Dual number into a container for Floats. But Julia doesn't tell me this, it tells me I tried to put a
ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.UJacobianWrapper{ODEFunction{true,typeof(lorenz),UniformScaling{Bool},Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing},Float64,DiffEqBase.NullParameters},Float64},Float64,3}into a container for floats. Is all of that necessary to the average user? I think there should probably be a way to limit this information, i.e.ForwardDiff.Dual{...}.However, it's not as simple as just doing that to all type parameters since here we wanted to know that it's:
so we need to print the
Float64but omit the other part.Remedy
My proposed remedy is a system like
show_simplified_typewhere a package can choose the simplified printing form of its type. SoForwardDiff.Dualcan defineForwardDiff.Dual{...,Float64}as its simplified print out, and by default this is all that's shown. Then in the expanded stacktrace forms of #36026 it could be set to give the entire information, but I think this will be a lot more helpful for the vast majority of people.The text was updated successfully, but these errors were encountered: