Better output for GenericExecutionStats (show vs print) (Pluto display)

[abelsiqueira]

This is moved from JuliaSmoothOptimizers/SolverTools.jl#93
To define the issue better:

The is a show method in https://github.com/JuliaSmoothOptimizers/SolverCore.jl/blob/main/src/stats.jl#L405
And a print method right below.

This means that on the REPL, the output of

output = trunk(nlp)

is

"Execution stats: first-order stationary"

And to see details, you have to use

print(output)

Which shows

Generic Execution stats
  status: first-order stationary
  objective value: 1.2067821564748022e-25
  primal feasibility: 0.0
  dual feasibility: 3.0567567125153457e-13
  solution: [0.99999999999966  0.9999999999992844]
  iterations: 10
  elapsed time: 0.0009999275207519531

At least in Pluto notebooks, I want the initial call output = trunk(nlp) to show the complete output.
From the little I gathered, there are two strategies:

1. Don't have a separate print functions, instead, put everything in show; or
2. Use MIME types to show a different output for Pluto (which I guess is related to HTML).

I like option 2 more. @tmigot @dpo, opinions?

There is some information about display vs show vs print in this JuliaCon 2020 video: https://www.youtube.com/watch?v=S1Fb5oNhhbc that might be useful.

---

To reproduce, open a Pluto notebook and add the following cells:

Cell 1

using ADNLPModel, JSOSolvers

Cell 2

let
nlp = ADNLPModel(x -> (x[1] - 1)^2 + 4 * (x[2] - x[1]^2)^2, [-1.2; 1.0])
output = trunk(nlp)
end

---

There is also a compact::Bool flag in show, that might be enough to have a single function with everything.

[abelsiqueira]

@Jay-sanjay, if you want to work on this, can you try implementing strategy 2?

[tmigot]

I like the idea of having a more informative output, and even better if it shows nicely on Pluto.