InfixUnions.jl

InfixUnions defines 3 separate infix operators that can be used to define Union types: |, ∪, and ∨. Since | and ∪ are defined and exported by Base, InfixUnions also defines a fallback method which forwards non-type arguments to the functions in Base. InfixUnions.jl does not commit type piracy on these functions.

In order to use InfixUnions, simply choose which operator you want with a using statement, and go:

using InfixUnions: |

struct Foo
    data::(Int|Nothing)
end

julia> Foo(1)
Foo(1)

julia> Foo(nothing)
Foo(nothing)

julia> true | false # Fallback to the Base method
true

Similarly, one can use the ∪ operator (written by typing \cup and then hitting the TAB key)

using InfixUnions: ∪ 

f(x::(Number ∪ Missing)) = 2x + 1

julia> f(1)
3

julia> f(missing)
missing

And the ∨ operator (written by typing \vee and then hitting the TAB key)

using InfixUnions: ∨

g(x::(Number ∨ Missing)) = (x - 1)/2

julia> g(1)
0.0

julia> g(missing)
missing