Type inference for a singleton of type Function

[oheil]

A more deep reasoning can be found here:

What is typeof(fun)?

when I methods(Base.map), I see something like: [1] map(::typeof(zero), A::BitArray) in Base at bitarray.jl:1659 what is typeof(zero)? indeed, I found that: julia> f(x) = 2x f (generic function with 1 method) julia> typeof(f) typeof(f) julia> typeof(f) <: Function true julia> typeof(f) isa DataType true julia> f isa Function true it’s quite strange to me: why typeof(f) not return Function? official docs mentions nothing about it.