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enumsjuliasymbols

Converting enums to symbols in Julia

I have a definition of an enum as below. I would like to map each instance of the enum into the corresponding symbol. I can do this by manually constructing an array symbols and indexing into it. Is there a way of accomplishing this without specifying the array of symbols by hand?

@enum MyEnum A=1 B=2 C=3

symbols = [:A, :B, :C]

function enumToSymbol(x::MyEnum) :: Symbol
    return symbols[Int(x)]
end

@assert enumToSymbol(A) == :A
Solution

  • Just use Symbol:

    julia> @enum MyEnum A=1 B=2 C=3

julia> Symbol(A)
:A

julia> x = A
A::MyEnum = 1

julia> Symbol(x)
:A

    as it is defined as follows:

    Base.Symbol(x::Enum) = namemap(typeof(x))[Integer(x)]::Symbol

    in particular you have an un-exported:

    julia> Base.Enums.namemap(typeof(x))
Dict{Int32,Symbol} with 3 entries:
  2 => :B
  3 => :C
  1 => :A