Vexil

An Elixir flag parser that does just enough.

Vexil is a CLI flag parsing library for Elixir, intended to be used in places where you might want to parse user input akin to how command line arguments are parsed, but in an area where you aren't getting the input from an actual command line, say a website or a chat platform bot.

I found OptionParser's settings to be too confusing for me, and Optimus is intended for use in regular command line application (with the in-built help and closing the application when encountering input errors), so Vexil slots in between the two as a sort of middle ground, letting you control how errors are displayed/handled for the user, and still having a sane interface for defining flags and options.

---

Vexil is currently beta-quality software, but is well tested with over 90% coverage at time of writing, including most standard usage scenarios for it. Until proper documentation is written and it has been sufficiently tested in a real-world application however, it will staying in ZeroVer and certain aspects of its functionality may change at any time until a stable 1.0 release.

Pull requests for bug fixes are welcome, including corresponding tests to make sure they actually work for what it is they're trying to fix.

Installation

Add vexil to your dependencies in mix.exs.

def deps do
  [{:vexil, "~> 0.1"}]
end

Example

iex> argv = "--end-at 256 -vvv some stuff after" |> OptionParser.split()
["--end-at", "256", "-vvv", "some", "stuff", "after"]
iex> options = [
...>   options: [
...>     end_at: %Vexil.Structs.Option{
...>       short: "e",
...>       long: "end-at",
...>       parser: :integer, # Default `:string`
...>       required: true
...>     }
...>   ],
...>   flags: [
...>     verbose: %Vexil.Structs.Flag{
...>       short: "v",
...>       long: "verbose",
...>       multiple: true
...>     }
...>   ]
...> ]
iex> {:ok, values, {option_errors, flag_errors}} = Vexil.parse(argv, options)
{:ok,
 %{
   argv: ["some", "stuff", "after"],
   flags: %{verbose: 3},
   options: %{end_at: 256}
 }, {[], []}}
iex> argv2 = "-vvv some stuff after" |> OptionParser.split()
iex> {:ok, values, {option_errors, flag_errors}} = Vexil.parse(argv2, options)
{:ok, %{argv: ["some", "stuff", "after"], flags: %{verbose: 3}, options: %{}},
 {[{:error, :missing_required_options, [:end_at]}], []}}

This section will be updated as documentation is expanded.

License

Vexil is released under the MIT License, see the LICENSE file for details.