#6022: GHC infers over-general types -------------------------------------+------------------------------------- Reporter: simonpj | Owner: simonpj Type: bug | Status: closed Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.4.1 Resolution: duplicate | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: | Blocked By: None/Unknown | Related Tickets: #8883 Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Changes (by thomie): * status: new => closed * resolution: => duplicate * related: => #8883 Comment: I now realize HEAD does exactly that, see #8883. I'm not sure if an extra regression is needed, but here's what it would look like: {{{ $ cat T6022.hs module T6022 where f x = x + head $ ghc-7.9.20141125 T6022.hs [1 of 1] Compiling T6022 ( T6022.hs, T6022.o ) T6022.hs:2:1: Non type-variable argument in the constraint: Num ([a] -> a) (Use FlexibleContexts to permit this) When checking that ‘f’ has the inferred type f :: forall a. Num ([a] -> a) => ([a] -> a) -> [a] -> a }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/6022#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler