enums.jl

using BenchmarkTools

@enum Shape Rock Paper Scissors

function play(a::Shape, b::Shape)
    if a == b
        return 0
    elseif a == Paper && b == Rock
        return 1
    elseif a == Paper && b == Scissors
        return 2
    elseif a == Rock && b == Scissors
        return 3
    else
        return play(b, a)
    end
end

getv() = rand([Paper, Rock, Scissors], 10_000)
A = getv()
B = getv()
@btime play.(A, B)

types.jl

using BenchmarkTools

abstract type Shape end
struct Rock     <: Shape end
struct Paper    <: Shape end
struct Scissors <: Shape end
play(::Type{Paper}, ::Type{Rock})     = 1
play(::Type{Paper}, ::Type{Scissors}) = 2
play(::Type{Rock},  ::Type{Scissors}) = 3
play(::Type{T},     ::Type{T}) where {T<: Shape} = 0
play(a::Type{<:Shape}, b::Type{<:Shape}) = play(b, a) # Commutativity
getv() = rand([Paper, Rock, Scissors], 10_000)
A = getv()
B = getv()
@btime play.(A, B)