def deps do
  [
    {:ex_pression, "~> 0.5.0"}
  ]
end

iex> ExPression.eval("exit(self())")
{:error, %ExPression.Error{name: "UndefinedFunctionError", message: "Function 'self/0' was referenced, but was not defined", data: %{function: :self}}}

iex> ExPression.eval("""
{
  "name": "ex_pression",
  "deps": ["xpeg"]
}
""")
{:ok, %{"name" => "ex_pression", "deps" => ["xpeg"]}}

iex> ExPression.eval(~s/{"1": "en", "2": "fr"}[str(int_code)]/, bindings: %{"int_code" => 1})
{:ok, "en"}

defmodule MyFunctions do
  # use $ special symbol in expressions
  def handle_special("$", date_str), do: Date.from_iso8601!(date_str)
  # Use diff function in expressions
  def diff(date_1, date_2), do: Date.diff(date_1, date_2)
end
iex> ExPression.eval(~s/diff($"2023-02-02", $"2022-02-02")/, functions_module: MyFunctions)
{:ok, 365}