 end
 
 defmodule BadMapError do
-  defexception [term: nil]
+  defexception [:term]
 
   def message(exception) do
     "expected a map, got: #{inspect(exception.term)}"

end

defmodule TryClauseError do
  defexception [term: nil]

  def message(exception) do
    "no try clause matching: #{inspect(exception.term)}"

end

defmodule TokenMissingError do
  defexception [:file, :line, description: "expression is incomplete"]

  def message(%{file: file, line: line, description: description}) do
    Exception.format_file_line(file && Path.relative_to_cwd(file), line) <>
