Which stable GHC release is expected to have support for linear types?

[Simon Peyton Jones]

And, just to be clear, while I think the design is coming along nicely, we have not yet made a clear proposal to the ghc-devs community, via the ghc-proposals mechanism, for a change to GHC.   Until we have an adopted propsoal we can't say "it'll be in GHC by date X".

Simon

|  -----Original Message-----
|  From: ghc-devs [mailto:ghc-devs-bounces at haskell.org] On Behalf Of
|  Boespflug, Mathieu
|  Sent: 30 June 2017 15:02
|  To: Wolfgang Jeltsch <wolfgang-it at jeltsch.info>
|  Cc: Arnaud Spiwack <arnaud.spiwack at tweag.io>; ghc-devs <ghc-
|  devs at haskell.org>
|  Subject: Re: Which stable GHC release is expected to have support for
|  linear types?
|  
|  Hi Wolfgang,
|  
|  8.4 is the next release after the (by now imminent) 8.2 release. But
|  no support for linear types has of yet been merged into the master
|  branch that will eventually form the basis of the 8.4 release. This
|  support is under active development at the moment on a side branch.
|  Some of us are giving ourselves the 8.4 release as a *tentative*
|  target, so don't count on it. It may well end up happening much
|  further in the future. It's a research effort at this point and the
|  design is likely to change a bunch.
|  
|  In the meantime, you can play around with this Docker image:
|  
|  https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fhub.d
|  ocker.com%2Fr%2Ftweag%2Flinear-
|  types%2F&data=02%7C01%7Csimonpj%40microsoft.com%7C0f0fa7d2181b498882bd
|  08d4bfc0b5c1%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636344281789
|  392239&sdata=aWCyABYfJdvkxZAVk4wD5IuErCPTYGvdFO22nbT8gYw%3D&reserved=0
|  
|  It contains a pre-built fork of GHC with the current state of the
|  linear types implementation. You can see the development as it's
|  happening here:
|  
|  https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithu
|  b.com%2Ftweag%2Fghc%2Ftree%2Flinear-
|  types&data=02%7C01%7Csimonpj%40microsoft.com%7C0f0fa7d2181b498882bd08d
|  4bfc0b5c1%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636344281789392
|  239&sdata=IGDxDD1q%2BxTRK%2FFwS0C%2BsDEpwFzbzHja4sF3twlF55c%3D&reserve
|  d=0
|  
|  Best,
|  --
|  Mathieu Boespflug
|  Founder at
|  https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Ftweag.
|  io&data=02%7C01%7Csimonpj%40microsoft.com%7C0f0fa7d2181b498882bd08d4bf
|  c0b5c1%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636344281789392239
|  &sdata=qXdzC81GzESKMHKCykOyM75XrPRbFL8edpsxKKv5VVQ%3D&reserved=0.
|  
|  
|  On 30 June 2017 at 15:49, Wolfgang Jeltsch <wolfgang-it at jeltsch.info>
|  wrote:
|  > Hi!
|  >
|  > The blog post on
|  >
|  https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fblog.t
|  > weag.io%2Fposts%2F2017-03-13-linear-
|  types.html&data=02%7C01%7Csimonpj%
|  >
|  40microsoft.com%7C0f0fa7d2181b498882bd08d4bfc0b5c1%7C72f988bf86f141af9
|  >
|  1ab2d7cd011db47%7C1%7C0%7C636344281789392239&sdata=i8wFqX5an5LyuBKQ5Jk
|  > 2q8jUQdb62l72wOj9OX1OoK0%3D&reserved=0
|  > says, “We are targeting a merge by the time of the 8.4 release of
|  GHC.”
|  > Does this mean that GHC 8.4 is expected to have support for linear
|  > types, or does it mean that the merge should happen after a GHC 8.4
|  > branch has been forked off from the HEAD branch, so that only GHC
|  8.6
|  > will have support for linear types?
|  >
|  > All the best,
|  > Wolfgang
|  > _______________________________________________
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