typeof(myFunction) does not work for a self-defined function myFunction

General Usage
1

julia> function myFunction()
println(“haha, you die”)
end
myFunction (generic function with 1 method)

julia> println(“type of myFunction:”, typeof(myFunction))
type of myFunction:typeof(myFunction)

a bit strange, right?

2

What do you mean “does not work”?

The type of a function is written like that:

julia> typeof(myFunction)
typeof(myFunction)
3

for example

julia> test(x) = false
julia> test(x::typeof(length)) = true
julia> test(sizeof)
false
julia> test(length)
true
4

I mean, it should have returned like the following:

julia> typeof(myFunction)
Function

5

I do not quite understand what do you mean exactly.

6

typeof(myFunction) does not return Function, it returns the type of myFunction which is written
“typeof(myFunction)” because each function has its own type (unlike many data structures).

You can use Function: isa(myFunction, Function) is true.

also supertype(typeof(myFunction)) == Function

2 Likes
7

You mean Function is a super type of all the self-defined functions? Could you give some examples?

8

Function is the immediate supertype of all the functions you use, including self-defined ones.

super(x) = supertype( typeof(x) )

super(sizeof) == Function
super(string) == Function

test(x) = true
add(x,y) = x+y

super(test) == Function
super(add) == Function
5 Likes