#11451: Inconsistent warnings for unused binders in type and instance declarations -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: patch Priority: normal | Milestone: 8.0.1 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: | Differential Rev(s): Phab:D1825 Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott <ryan.gl.scott@…>): In [changeset:"6817703b31840620cca8596ca62ed70633934972/ghc" 6817703/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="6817703b31840620cca8596ca62ed70633934972" Split off -Wunused-type-variables from -Wunused-matches Summary: Previously, `-Wunused-matches` would fire whenever it detected unused type variables in a type family or data family instance. This can be annoying for users who wish to use type variable names as documentation, as being `-Wall`-compliant would mean that they'd have to prefix many of their type variable names with underscores, making the documentation harder to read. To avoid this, a new warning `-Wunused-type-variables` was created that only encompasses unused variables in family instances. `-Wunused-matches` reverts back to its role of only warning on unused term-level pattern names. Unlike `-Wunused-matches`, `-Wunused-type-variables` is not implied by `-Wall`. Fixes #11451. Test Plan: ./validate Reviewers: goldfire, ekmett, austin, hvr, simonpj, bgamari Reviewed By: simonpj, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1825 GHC Trac Issues: #11451 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11451#comment:36> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler