
Yes, but it is not feasible before GHC 8.6, due to needing GHC >= 8.2 for
bootstrapping.
On 22 November 2017 at 15:26, GHC
#14490: TTG Snags -------------------------------------+---------------------- --------------- Reporter: alanz | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #14482 | Differential Rev(s): Wiki Page: | ImplementingTreesThatGrow | -------------------------------------+---------------------- ---------------
Comment (by Shayan-Najd):
So making a Data instance per concrete version may be the best way to go. Plan B.
Regardless of the GHC version we use, the question is whether Plan B really fixes the build-time problem. Can we test it?
-- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14490#comment:31 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

Yes, but it is not feasible before GHC 8.6, due to needing GHC >= 8.2 for bootstrapping.
True. But 8.4 will fork off shortly; so once that is done, we are happy with perf, we can add the change to master in preparation for 8.6.
Simon
From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf Of Alan & Kim Zimmerman
Sent: 22 November 2017 13:30
To: ghc-devs@haskell.org
Subject: Re: [GHC] #14490: TTG Snags
Yes, but it is not feasible before GHC 8.6, due to needing GHC >= 8.2 for bootstrapping.
On 22 November 2017 at 15:26, GHC
So making a Data instance per concrete version may be the best way to go. Plan B.
Regardless of the GHC version we use, the question is whether Plan B really fixes the build-time problem. Can we test it? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14490#comment:31https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fghc.haskell.org%2Ftrac%2Fghc%2Fticket%2F14490%23comment%3A31&data=02%7C01%7Csimonpj%40microsoft.com%7C3556984203554207d6c008d531ad467b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636469542646255358&sdata=s6kHeirmxaeW%2BRTX%2BPLHZl6UriqamOJcUlofDk5UogM%3D&reserved=0> GHC <http://www.haskell.org/ghc/https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.haskell.org%2Fghc%2F&data=02%7C01%7Csimonpj%40microsoft.com%7C3556984203554207d6c008d531ad467b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636469542646255358&sdata=Y9ezk0w89tcdtlLvJpgvYXgWc6iehBhs9kBfEREP9bM%3D&reserved=0> The Glasgow Haskell Compiler
participants (2)
-
Alan & Kim Zimmerman
-
Simon Peyton Jones