Understanding Julia documentation syntax

General Usage
1

I’ve decided to familiarize myself with the documentaion system in Julia.
For that, I am looking through the source Julia code as the source of inspiration.

However, I have encountered a puzzling syntax in one of the source files.
Specifically, in base/abstractarrays.jl:

"""
    AbstractArray{T,N}
Supertype for `N`-dimensional arrays (or array-like types) with elements of type `T`.
[`Array`](@ref) and other types are subtypes of this. See the manual section on the
[`AbstractArray` interface](@ref man-interface-array).
"""
AbstractArray

Here, I see a docstring for abstract type AbstractArray. I expected that it should be followed by the definition of the type

abstract type AbstractArray{T,N} end

Instead, it is followed simply by AbstractArray. Could anyone explain this syntax to me, please?

2

My guess is that it is there solely for the purpose of documentation.
The actual type is probably defined somewhere else.

3

Built-ins need a placeholder for the docstrings.

For user-defined types, you don’t need to worry about this.

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