
#11224: Program doesn't preserve semantics after pattern synonym inlining. -------------------------------------+------------------------------------- Reporter: anton.dubovik | Owner: Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 7.10.2 Resolution: | Keywords: | PatternSynonyms Operating System: Windows | Architecture: x86_64 Type of failure: Incorrect result | (amd64) at runtime | Test Case: Blocked By: | Blocking: Related Tickets: #11225 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): Replying to [comment:10 mpickering]:
That sounds right Richard but there is also another bug here that inlining the synonym changes the semantics. That shouldn't get lost either.
Yes. We need to test that. But I think the problem is due to universal/existential confusion when implementing pattern synonyms, and that sorting it out will fix the original bug. This assumption could very well be wrong. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11224#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler