Simulates Variadic functions in Elixir (i.e functions with an unknown number of arguments)
Arguments will named arg1, arg2....argN
where N
is @max_arity
.
Uninitialized arguments are set to the atom :no_args_at_this_position
NOTE: Currently doesn't support guards in the function head
defmodule MyTestModule do
import Variadic
##
## Functions are defined as defv (they will be public)
##
defv :test_function do
# If arguments needed as a list or need arity then binding() should be the first thing called
arguments = args_to_list(binding())
work = arg1 + arg2
{arg1, arg2, arg3, arg4, work, arguments}
end
defv :other_function do
binding = binding()
## Do work
x = 1 + 2 + 3
arguments = args_to_list(binding)
arity = get_arity(binding)
{arg1, arg2, x, [arity: arity, arguments: arguments]}
end
end
From the shell:
Pass 3 arguments (note arg4 is nil):
iex(2)> MyModule.test_function(1, 2, :hello)
{1, 2, :hello, :no_args_at_this_position, 3, [1, 2, :hello]}
Pass 10 arguments:
iex(3)> MyModule.test_function(1, 2, :hello, 4, 5, 6, :bye, %{key: 123}, [771,"something"], 10)
{1, 2, :hello, 4, 3, [1, 2, :hello, 4, 5, 6, :bye, %{key: 123}, [771, "something"], 10]}
Show binding
iex(10)> MyModule.other_function(777, 888, 999)
{777, 888, 6, [arity: 3, arguments: [777, 888, 999]]}
Helper functions: get_arity/1
and args_to_list/1