ERL-681: Allow trailing commas in lists and tuples

[OTP-Maintainer]

Original reporter: vassilevsky
Affected version: Not Specified
Component: Not Specified
Migrated from: https://bugs.erlang.org/browse/ERL-681

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Hello :)

New Erlang user here :)

It would have been really nice to be able to put commas at the end of every element in a vertically formatted list or a tuple.

There has been EEP 21 (http://erlang.org/eeps/eep-0021.html) — what has happened to it?

[OTP-Maintainer]

mikael pettersson said:

Even if it's easy to implement, the fact that the EEP has been sitting there for so long with no followups indicates that this isn't viewed as a big problem in the Erlang community.

I agree that having to change (insert or delete) a comma on an adjacent line when adding or deleting an item in a vertical list (including records, tuples and argument lists) is annoying.  In our code base (Klarna) we like to use a "comma first" style for those which avoids the problem, .e.g.

{noformat}
-export([ foo/0
        , fie/1
        , fum/2
        ]).
{noformat}

I you _really_ want the "allow comma after last item" feature you need to implement it and submit a PR, or convince someone else to do so.  Also, this is perhaps best brought up on the erlang-questions mailing list and not issued as a bug report.