Trailing commas + mix format

[marcandre]

For people that love trailing commas, I released v2.0 of the freedom formatter. It is now a plugin for the builtin formatter (requires Elixir 1.13.2+).

Note that elixir-ls’s next release will support formatting plugins.

Thanks to José Valim for making formatter plugins possible , and Pete Gamache for the initial version of the freedom_formatter.

[Sebb]

What do you think about adding tabular code formatting?

Do you use formatter in your elixir project?

I love tabular code. This defp decode(addr_t(:ind), _dest, data) do case data do <<0::6, data::bits>> -> {:t_data_ind, nil, data} <<0b01::2, seq::4, data::bits>> -> {:t_data_con, seq, data} <<0b1000_0000::8>> -> {:t_connect, nil, <<>>} <<0b1000_0001::8>> -> {:t_discon, nil, <<>>} <<0b11::2, seq::4, 0b10::2>> -> {:t_ack, seq, <<>>} <<0b11::2, seq::4, 0b11::2>> -> {:t_nak, seq, <<>>} _ …

And what do you think about making the formatter bringing all clauses to a single line when possible, eg here when the inspect is removed:

case number do
  1 ->
    :one

  2 ->
    :two

  3 ->
    :three

  number ->
    IO.inspect(number)
    :very_big
end

[marcandre]

Thanks for your question and interest

I welcome PRs for new features. At first sight, both of these seem acceptable. Care must be taken into when they would trigger or not and have good test coverage.

I personally do not intend to actually write the implementation for any new option. Trailing commas is what I am interested in. It is in my mind a different beast than the rest because it is not about readability or esthetics, it is about ease of editing and about minimizing diffs. I doubt I will propose to my colleagues to use other formatting options.

If someone else writes them, I will gladly review them and maintain them though.

[AstonJ]

For anyone interested, there’s a thread about trailing commas here:

Do you always add a trailing comma?

EG: defp deps do [ {:phoenix, "~> 1.4.1"}, {:phoenix_pubsub, "~> 1.1"}, {:phoenix_ecto, "~> 4.0"}, ] end Or do you prefer not to? defp deps do [ {:phoenix, "~> 1.4.1"}, {:phoenix_pubsub, "~> 1.1"}, {:phoenix_ecto, "~> 4.0"} ] end

[arcanemachine]

I stumbled on this thread after getting yet another compilation error from shuffling around the values in a long list (obviously, I moved the last one somewhere else in the list).

I think trailing commas are ugly, but they are simply more functional: Cleaner diffs, and makes it easier to shuffle values around.

Thanks for making this project! One less annoyance to babysit.