dynamic_docs_makie.jl

using Markdown

Docs.getdoc(s::typeof(scatter)) = plot_func_docs(s)
Docs.getdoc(h::typeof(heatmap)) = plot_func_docs(h)


function plot_func_docs(plotfunc)
    T = Combined{plotfunc}
    io = IOBuffer()

    trait = Makie.conversion_trait(T)
    println(io, "# Type signatures")
    println(io, "`$plotfunc` has the conversion trait `$trait` which means that it accepts the following positional arguments:\n")

    conversion_trait_docs(io, trait)

    Markdown.parse(String(take!(io)))
end

function conversion_trait_docs(io, trait)
    ms = methodswith(typeof(trait), Makie.convert_arguments, supertypes = true)

    argspecs = [method_argspec(m)[2:end] for m in ms]

    sort!(argspecs, by = length)
    
    for argspec in argspecs
        print(io, "- ")
        for (i, arg) in enumerate(argspec)
            print_sig(io, arg)
            i < length(argspec) && print(io, ", ")
        end
        println(io)
    end
end

function print_sig(io, pair)
    print(io, pair[1], "::`", pair[2], "`")
end

function method_argspec(m::Method)
    argnames = ccall(:jl_uncompress_argnames, Vector{Symbol}, (Any,), m.slot_syms)
    isempty(argnames) && return []

    f(x::Type) = x isa UnionAll ? x.body.parameters[2:end] : x.parameters[2:end]
    try
        [a=>b for (a,b) in zip(argnames[2:m.nargs], f(m.sig))]
    catch e
        []
    end
end