#15247: Use empty types for TTG extension constructors -------------------------------------+------------------------------------- Reporter: adamgundry | Owner: (none) Type: task | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.5 Resolution: | Keywords: TTG Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Shayan-Najd): Hi Adam, Take a look at [wiki:ImplementingTreesThatGrow/TreesThatGrowGuidance], there we use the "standard" empty type `Void` and its eliminator `absurd` from `Data.Void`. Currently, TTG does not fully follow the guidelines as the extension constructors are barely used. I will soon have a pass over the current TTG implementation and fix it to match the guidelines. As we used `NoExt` instead of `()`, we can possibly use a GHC-Specific empty datatype instead of `Void`. Is there anything else that I may be missing? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15247#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler