Lisp Parser

lisp.exs

defmodule Lisp do
  @doc "Removes the wrapping parenthesis and breaks the expression up into individual arguments and sub-expressions, then parses each of those"
  def parse("(" <> lisp) do
    remove_parens = String.slice(lisp, 0..-2)
    Regex.scan(~r/(?:\(.*\)|[^\s]+)/, remove_parens)
    |> List.flatten
    |> Enum.map(&parse/1)
  end

  @doc "parses individual operators and arguments. Currently all it does is convert numbers"
  def parse(lisp) do
    if lisp =~ ~r/\d+/ do
      String.to_integer(lisp)
    else
      lisp
    end
  end
end