On 23/09/14 10:11, Alexander Berntsen wrote:
On 22/09/14 21:07, Simon Peyton Jones wrote:
have a language extension TrailingCommas (or something) to enable the extension For clarification: are you overruling the "do we sneak it in HEAD or use pragma(s)"-vote and telling me to do the latter?
If we can sneak it into HEAD (this is @ you Johan, too), I suggest that someone applies my patches to make import and export lists support leading commas (presently they only support trailing commas, per the report) -- and following this I can just send a bunch of "Permit leading/trailing ',' in Foo" patches to Phabricator, and you guys can bikeshed over there about which ones you actually want to commit. ;-)
If I am to go down the pragma route, I guess I can make a RudundantCommas pragma or something like that, that implements trailing commas for imports/exports, and leading/trailing commas for the suggestions in this thread.
I'm +1 on the GHC HEAD route, but I'm not exactly violently opposed to the pragma route either.
Here's my reasoning: If you invoke ghc with -XHaskell2010, then trailing commas shouldn't be accepted, because they do not belong to Haskell 2010. Which means that you do need an extension to identify this difference in behavior. Roman