Julia recursive deep copy and merge for nested dicts

function deep_clone(x)
    x isa AbstractDict && return Dict(k => deep_clone(v) for (k, v) in x)
    x isa AbstractVector && return [deep_clone(v) for v in x]
    return x
end

function deep_merge(base, patch)
    out = deep_clone(base)
    for (k, v) in patch
        if haskey(out, k) && out[k] isa AbstractDict && v isa AbstractDict
            out[k] = deep_merge(out[k], v)
        else
            out[k] = deep_clone(v)
        end
    end
    return out
end

base = Dict("db" => Dict("host" => "localhost", "port" => 5432))
println(deep_merge(base, Dict("db" => Dict("port" => 6543))))