Julia: Get body of a function

Question

How can I access the body of a function?

Context: I have functions inside modules which I execute with specific parameter values. I want to "keep a record" of these parameter values and corresponding functional forms. Below my attempt:

module MyModule

using Parameters  # Parameters provides unpack() macro
using DataFrames  # DataFrames used to store results in a DataFrame

struct ModelParameters
    γ::Float64
    U::Function
end

function ModelParameters(;
    γ = 2.0,
    U = c -> if γ == 1.0; log(c); else (c^(1-γ)-1)/(1-γ) end
    )
    ModelParameters(γ, U)
end

function show_constants(mp::ModelParameters)
    @unpack γ = mp
    d = DataFrame(
        Name = ["γ"],
        Description = ["parameter of U"],
        Value = [γ]
    )
    return(d)
end

function show_functions(mp::ModelParameters)
    @unpack U = mp
    d = DataFrame(
        Name = ["U"],
        Description = ["function with parameter γ"],
        Value = [U]
    )
    return d
end


export
ModelParameters
show_constants,
show_functions

end  # end of MyModule

Keeping a record:

using Main.MyModule
mp = ModelParameters()

MyModule.show_constants(mp)

1×3 DataFrame
 Row │ Name    Description     Value   
     │ String  String          Float64 
─────┼─────────────────────────────────
   1 │ γ       parameter of U      2.0


MyModule.show_functions(mp)

1×3 DataFrame
 Row │ Name    Description                Value 
     │ String  String                     #2#4… 
─────┼──────────────────────────────────────────
   1 │ U       function with parameter γ  #2

This is quite useful to store scalars and arrays value, but not for functions. How could I replace #2 with something useful?

Examples of what would be useful:

c -> if γ == 1.0; log(c); else (c^(1-γ)-1)/(1-γ) end,

or

(c^(1-2.0)-1)/(1-2.0)

or (magically simplified):

1-c^(-1.0)

My question is somewhat related to Julia: show body of function (to find lost code).

Julia: Get body of a function

1 Answers