Peon

Peon (Pure Elixir Object Notation) is a simple library for using Elixir maps as a document storage format. Maps are simply saved as files and evaluated when loaded.

Usage

Map data can be written to and read from files with the .peon extension:

data = %{
  hello: {"world", 42, :foo}
}
filename = "data.peon"
{:ok, filename} = Peon.to_file(data, filename)
{:ok, data} = Peon.from_file("data.peon")

Safety

from_file will return {:error, message} when attempting to load a file that could execute arbitrary code. Peon traverses a map's AST and rejects it if it finds any expression tuple that doesn't have :{} or %{} as its first element.

You can bypass this using Peon.from_file!. This function also allows passing a keyword list as a second argument, which is used to bind unbound variables found in the loaded file. For example, given the following file unsafe.peon:

%{
  group: :users,
  language: String.capitalize(language),
  name: name
}

...the following will return true:

{:ok, data} = Peon.from_file("unsafe.peon", [name: "José Valim", language: "elixir"])
Map.equal?(data, %{
  group: :users,
  language: "Elixir",
  name: "José Valim"
}

License

MIT