GHC 7.8 release?

Simon Peyton-Jones simonpj at
Thu Feb 7 09:25:10 CET 2013

Dear GHC users,

Carter: Will this RTS update make it into ghc 7.8 update thats coming up in the next monthish?
Andreas: We are almost there - we are now trying to sort out a problem on mac os x. It would be helpful to know if there is a cutoff date for getting things into 7.8.

Simon, Ian, and I have just been discussing 7.8, and would be interested in what you guys think.

At ICFP we speculated that we'd make a release of GHC soon after Christmas to embody tons of stuff that has been included since 7.6, specifically:

·         major improvements in DPH (vectorisation avoidance, new vectoriser)

·         type holes

·         rebindable list syntax

·         major changes to the type inference engine

·         type level natural numbers

·         overlapping type families

·         the new code generator

·         support for vector (SSE/AVX) instructions

Whenever it comes it would definitely be great to include Andreas & friends' work:

·         Scheduler changes to the RTS to improve latency

The original major reason for proposing a post-Xmas release was to get DPH in a working state out into the wild.  However, making a proper release imposes costs on everyone else.  Library authors have to scurry around to make their libraries work, etc.   Some of the new stuff hasn't been in HEAD for that long, and hence has not been very thoroughly tested.   (But of course making a release unleashes a huge wave of testing that doesn't happen otherwise.)

So another alternative is to leave it all as HEAD, and wait another few months before making a release.  You can still use all the new stuff by compiling HEAD, or grabbing a snapshot distribution.  And it makes it hard for the Haskell platform if GHC moves too fast. Many people are still on 7.4.

There seem to be pros and cons each way.  I don't have a strong opinion.  If you have a view, let us know.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the Glasgow-haskell-users mailing list