Visualize the Julia Type Tree

Question

Is there a convenient way to visualize the Julia type tree? I know I can write a function for that...

function ttree(t::Type, indent = "    ")
    println(string(indent, t))
    indent *= "    "
    for st in subtypes(t)
        ttree(st, indent)
    end
end

ttree(Integer)

    Integer
        Bool
        Signed
            BigInt
            Int128
            Int16
            Int32
            Int64
            Int8
        Unsigned
            UInt128
            UInt16
            UInt32
            UInt64
            UInt8

...but Julia's strong pronunciation of multiple dispatch makes me feel like there must be some cool built-in function for that, right?

Answer 1

Use GraphRecipes:

using GraphRecipes, Plots
plot(Integer, method=:tree, fontsize=10, nodeshape=:rect)

Here is an ASCII approach

using AbstractTrees
AbstractTrees.children(d::DataType) = subtypes(d)

And here it is in action

julia> print_tree(Integer)
Integer
├─ Bool
├─ Signed
│  ├─ BigInt
│  ├─ Int128
│  ├─ Int16
│  ├─ Int32
│  ├─ Int64
│  └─ Int8
└─ Unsigned
   ├─ UInt128
   ├─ UInt16
   ├─ UInt32
   ├─ UInt64
   └─ UInt8

Answer 2

Term.jl provides a typestree function that produces a beautiful tree of types:

But it only seems to go upwards i.e. the supertype hierarchy of a given type. An option to dig down to get lower level subtypes doesn't (as of Term v1.0.4) seem to exist. It does print out the immediate subtypes of a type, just not the levels down from those.