Define Dynamic Functions with Dynamic Arguments (Arity) using Elixir Macros

There are two ways of dynamic function creation with arity using Elixir Macros. For both of the ways, the first thing is creating dynamic args:

defp create_args(_, 0),
  do: []
defp create_args(fn_mdl, arg_cnt),
  do: Enum.map(1..arg_cnt, &(Macro.var (:"arg#{&1}"), fn_mdl))

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First way is creating function without any arguments with a simple unquote do yield and then putting arguments inside the non-argumented function using `Macro.prewalk` or `Macro.postwalk`:

defmacro dynamic_fn_without_arity(fn_name) do
  quote do
    # We can specify documentation for the function
    @doc false
    def unquote(fn_name)() do
      # IO.inspect(arg1)
      # IO.inspect(arg2)
    end
  end
end
## Usage
fn_name = :some_new_fn
fn_args = create_args(SomeModule, 2)
ast = dynamic_fn_without_arity(fn_name)
# Here we are injecting args to our dynamic function
Macro.postwalk(ast, fn
  ({ast_fn_name, context, []}) when ast_fn_name == fn_name ->
    {fn_name, context, fn_args}
  (other) -> other
end)

Second way of dynamic function creation with arity is `unquote_splicing` function:

defmacro dynamic_fn_with_arity(fn_name, fn_args) do
  quote do
    # We can specify documentation for the function
    @doc false
    def unquote(fn_name)(unquote_splicing(fn_args)) do
      # IO.inspect(arg1)
      # IO.inspect(arg2)
    end
  end
end
## Usage
fn_name = :some_new_fn
fn_args = create_args(SomeModule, 2)
dynamic_fn_with_arity(fn_name, fn_args)