#15798: Flag to warn when deriving strategy is not explicitly specified -------------------------------------+------------------------------------- Reporter: andrewthad | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.6.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- In my code, I aim to always specify deriving strategies. I would like to add a flag `-fwarn-unspecified-deriving` that would cause a warning to be emitted when someone wrote this: {{{ newtype Foo = Foo Int deriving (Show) }}} The user would be required to instead write: {{{ newtype Foo = Foo Int deriving newtype (Show) }}} Or they could use `stock` if that was the behavior they wanted. This flag would be off by default. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15798 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler