#9984: Show, Read, Eq, Ord instances for Control.Applicative.Const -------------------------------------+------------------------------------- Reporter: fumieval | Owner: Type: feature | Status: new request | Milestone: Priority: low | Version: 7.8.4 Component: | Operating System: Unknown/Multiple libraries/base | Type of failure: None/Unknown Keywords: | Blocked By: Architecture: | Related Tickets: Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- As mentioned in https://www.haskell.org/pipermail/libraries/2013-October/021531.html, the following instances can be derived clearly: * `Show a => Show (Const a b)` * `Read a => Read (Const a b)` * `Eq a => Eq (Const a b)` * `Ord a => Ord (Const a b)` The absence of these instances makes debugging harder. I suggest handcrafted Show/Read instances for neat representation. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9984 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler