#10681: Teach GHC to interpret all hs files as two levels of hs-boot files (abstract types only/full types + values) -------------------------------------+------------------------------------- Reporter: ezyang | Owner: ezyang Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by goldfire): ezyang says:
This seems to definitely suggest that you should never need more than two levels of hs-boot nesting, or perhaps three with kinding. (But maybe someone has a fancy type system feature for which this is not true!)
I believe I have such a fancy type system feature. My solution to #7961 (that is, my very long-running "nokinds" [https://github.com/goldfirere/ghc/ branch], due to be merged Any Season Now [at least it's better than Any Year Now]) merges types with kinds, allowing an arbitrary number of "levels". In other words, I think a pathological case can (if I understand your proposal here correctly) require an arbitrary number of hs-boot levels. For example: {{{ data A data B :: A -> * data C :: B a -> * data D :: C b -> * data E :: D c -> * }}} This compiles fine on my branch, but I believe would cause problems with this proposal. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10681#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler