#10134: Pattern Matching Causes Infinite Type Error -------------------------------------+------------------------------------- Reporter: dongen | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by goldfire): This smells like a "Let should not be generalised" problem. dongen: Does enabling the `MonoLocalBinds` extension fix the problem? Conversely, in your one-module, no-dependencies version, does enabling `NoMonoLocalBinds` cause the problem to appear? The `TypeFamilies` extension implies `MonoLocalBinds`. My guess is that this is a case where using definitions whose types mention type families means that a `let` should not be generalised. And that will be hard to fix without enabling `MonoLocalBinds` by default. Interesting -- I'd love to see that minimal case! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10134#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler