julia_type_hierarchy.jl

# Requested gist of code to produce:
#   https://www.scribd.com/doc/271871142/Julia-Type-Hierarchy
# 
# I just redirected the output to a dot file, then executed:
#    dot -Tpdf julia.dot -o julia.pdf
function print_type_tree(t, parent=Any, seen=Set{DataType}())
    # Avoid redundant edges.
    t ∈ seen && return 
    push!(seen, t)
    
    # Avoid self-edges.
    t != Any && println("""   "$t" -> "$parent";""")
    
    # Recurse, divine!
    for s in subtypes(t)
        print_type_tree(s, t, seen)
    end
end


println("digraph {")
print_type_tree(Any)
println("}")