# Limited amount of fields in mutable struct with macros

#1

Hello,

First thanks for this community to be so active, it’s the first out of many problems I could not find a solution to!

I am trying to create mutable structs with a rather large amount of fields ( ~30 ). These structs are very similar so int order to avoid code repetition I created multiple macros and saved the fields in them.
Now my problem is that my constructor does not find some of the fields.
After investigation, the missing fields are the ones which replaced by “⋮” when “calling fieldnames(name of struct)”

I tried to make a similar case (many fields) without the macros, but there everything works…
Any suggestion on this, I am using v0.6 by the way.

Thanks for you help. Théo

Code looks like

@def gaussianparametersfields begin
μ::Array{Float64,1}
η_1::Array{Float64,1}
ζ::Array{Float64,2}
η_2::Array{Float64,2}
end

mutable struct A
@commonfields
@gaussianparametersfields
@otherfields
*Some constructor*
end


#2

Please provide enough information for the code to be run. What is @def? What should I do to generate the error? Examples that can be copy pasted into the REPL are nice.

#3

@def is as defined in the documentation :

macro def(name, definition)
return quote
macro $(esc(name))() esc($(Expr(:quote, definition)))
end
end
end


My assumption on the error was wrong. It’s only a few fields that are not recognized. Here is the code that does not work

@def commonfields begin
#Data
X #Feature vectors
y #Labels (-1,1)
nSamples::Int64 # Number of data points
nFeatures::Int64 # Number of features
γ::Float64
nEpochs::Int64
µ_init::Array{Float64,1}
VerboseLevel::Int64
Stochastic::Bool
Autotuning::Bool
ρ_Θ::Array{Float64,1}
κ_Θ::Float64
τ_Θ::Int64
AutotuningFrequency::Int64
Trained::Bool
TopMatrixForPrediction
DownMatrixForPrediction
MatricesPrecomputed::Bool
end

mutable struct A
@commonfields
end

in(:ρ_Θ, fieldnames(A))


Return false for ρ_Θ, κ_Θ and τ_Θ

#4

What documentation? It is not a Base macro.

Anyway, I get:

julia> in(:ρ_Θ, fieldnames(A))
true

julia> in(:κ_Θ, fieldnames(A))
true

julia> in(:τ_Θ, fieldnames(A))
true


On julia v0.6.

#5

What documentation? It is not a Base macro.

It is indeed not in the Base macro, I misexplained myself, it is simply that I have seen many times suggested and thought it was somehow an “official” method.
Anyway, running this exact code still gives me a false statement.
But I just found the cause and this is very vicious:
ρ_Θ and ρ_Θ are not the same according to Julia. Although I wrote them everytime with \theta

(I am running Julia from Ubuntu btw)
Well thanks for your help, I will just change the names to something different

#6

One Greek symbol is uppercase, and one is lowercase?

#7

The thetas there seems to be the same to me? If you enter them in the REPL as a char, e.g:

julia> 'Θ'
'Θ': Unicode U+0398 (category Lu: Letter, uppercase)


what does it say for the two thetas?

#8

From \theta :

'θ': Unicode U+03b8 (category Ll: Letter, lowercase)


From fieldnames

'Θ': Unicode U+0398 (category Lu: Letter, uppercase)


My guess is that the macro interpretated the lowercase θ as an uppercase Θ while in the rest of the code the lowercase is used (without passing by a macro)

#10

Ah, like Petr says, this is just capital theta vs lowercase theta.