#9972: t7861 gives unexpected result (deferred type error) -------------------------------------+------------------------------------- Reporter: luite | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- I'm not sure why `validate` does not trip on this, but the test case does not look obviously disabled to me, so I thought I'd just report it so at least it doesn't get unnoticed. GHC 7.8: {{{ "Hello" t7861: t7861.hs:11:5: Couldn't match type ‘a’ with ‘[a]’ ‘a’ is a rigid type variable bound by the type signature for f :: A a -> a at t7861.hs:10:6 Expected type: A a -> a Actual type: A a -> [a] Relevant bindings include f :: A a -> a (bound at t7861.hs:11:1) In the expression: doA In an equation for ‘f’: f = doA (deferred type error) }}} On GHC 7.10 the result is (both with and without optimization) {{{ "Hello" "Bad" }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9972 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler