I’m trying to identify function calls. My current solution seems to be working, but I’m not sure what are the edge cases I should test for and I imagine there’s a better solution.

So far I determine a node is a function call if it is a triple, it’s third element is a list and it is not a special form.
So this {:foo, [], []} would be a function call, but this {:{}, [], []} wouldn’t and neither would this {:foo, [], nil}.

The code:

  # for functions calls or special forms with the same structure
  defmacro foo({call, _meta, args}) when is_list(args) do
    if Macro.special_form?(call, length(args)) do
      # do stuff if it ISN'T a function call
    else
      # do stuff if it IS a function call
    end
  end

  # for literals and variables
  defmacro foo(node) do
    # do stuff if it ISN'T a function call
  end

If you see any errors or know a better solution your help would be greatly appreciated!