Well you don't really want to "silence the warning from duplicate constructors/patterns within the list". You want to silence ''this'' duplicate of `Bar`. If you happen to repeat a different constructor elsewhere in the export list by accident, you'd still want a warning about
#12389: Limit duplicate export warnings for datatypes -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: feature request | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: #11959 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): Replying to [comment:5 rwbarton]: that. So it would more appropriate to use a mechanism for locally disabling warnings. Local suppression is very heavy for a warning about something as relatively unimportant as this. I'd be happy with a heuristic: accidental duplicates are typically less likely in a constructor/pattern export list than in a (typically much longer) module export list. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12389#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler