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