#9330: Introduce shortcut for "on (==)" much like there's a shortcut for "on compare". -------------------------------------+------------------------------------- Reporter: frerich | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.8.2 Component: | Keywords: libraries/base | Operating System: Unknown/Multiple Resolution: | Type of failure: None/Unknown Differential Revisions: | Test Case: Architecture: | Blocking: Unknown/Multiple | Difficulty: Unknown | Blocked By: | Related Tickets: | -------------------------------------+------------------------------------- Comment (by frerich): A lot of `*By` functions taking an `a -> a -> Bool` are in `Data.List`, e.g. `groupBy`, `nubBy`, `deleteBy`, `intersectBy`, `unionBy`. Hence, it seems plausible to define `equating` in `Data.List`. This is the same reasoning as why `comparing` is in `Data.Ord`: because the module exposes a lot of `*By` functions taking an `a -> a -> Ordering`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9330#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler