trailing commas followup

[adriaanm]

TODO:

• PR an update the spec: Update the spec for trailing commas (SIP-27) scala#5779
• PR an update the SIP: Final update to SIP-27 Trailing Commas docs.scala-lang#731
• PR scala.meta: Add support for trailing commas, fixes #657 scalameta/scalameta#660
• PR intellij-scala: JetBrains/intellij-scala@1ae1115 and JetBrains/intellij-scala@6ad57b6
• PR scalaparse: Add support for trailing commas com-lihaoyi/fastparse#145

[adriaanm]

Assigned Dale as the coordinator. Multiple people will be involved of course in checking all items off of this list

[olafurpg]

For anyone interested, I made a scalafix rewrite to insert missing trailing commas. Here's the diff from running the rewrite on a large corpus olafurpg/scala-repos#19 it's still a WIP, it might be nice to limit the rewrite to varargs (slow, but doable with the new semantic rewrites) or a configured whitelist of term applications such as List/Seq (fast, doable with syntax only).

[DavidDudson]

@olafurpg Does scalafmt have a PR yet?

[olafurpg]

Not yet. Scalafmt is still on meta 1.4, will wait for 1.6 which is due next week.

[dwijnand]

@SethTisue this is on the top of my out-of-hours TODO list. Lemme know if you need me to fast track it for 2.12.2 and I can try speaking to @eed3si9n.

[SethTisue]

Scalariform doesn't even have a 2.12 release at all afaik (scala-ide/scalariform#235), so that one isn't a blocker

presumably the spec and SIP updates will be merged

so perhaps the only pressing thing here is to make sure JetBrains is aware and has this in their pipeline for IntelliJ...?