falsify_vars_in_match.ex

defmodule Test do
  def falsify_var(contents) do
    IO.puts(inspect(contents))

    case contents do
      { :^, _, [_] } ->
        contents 
      { var, meta, scope } when is_atom(var) and is_atom(scope) ->
        { var, meta, false }
      { left, meta, right } ->
        { falsify_var(left), meta, falsify_var(right) }
      { left, right } ->
        { falsify_var(left), falsify_var(right) }
      list when is_list(list) ->
        lc i inlist list, do: falsify_var(i)
      other ->
        other
    end
  end

  defmacro new_match?(left, right) do
    left = falsify_var(left)

    quote do
      case unquote(right) do
        unquote(left) ->
          true
        _ ->
          false
      end
    end
  end

  def test(_a, b, c) do
    finder = new_match?({ ^b, _, d } when length(d) == c, &1)
    list = [{ 1, 2, [3] }, { 1, 2, [3] }]
    Enum.find(list, finder)

    new_match?(e, 1)

    Kernel.binding
  end
end

IO.puts(inspect(Test.test(1, 2, 3)))