#9066: Template Haskell cannot splice an infix declaration for a data constructor -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Template | Version: 7.8.2 Haskell | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: None/Unknown | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by goldfire): Harrumph. In that second case, {{{[d| infix 5 `Foo` |]}}} produces an `Exact` `RdrName` for `Foo` that names a ''data'' constructor, not a ''type'' constructor, even when only the type constructor is in scope. Then, according to `Note [dataTcOccs and Exact Names]` in !RnEnv, the `Exact` `RdrName`s are trusted to have the right namespace and, so a naive fix for this bug fails the `Foo` case. There are two possible ways forward that I see: 1. Don't trust `Exact` `RdrName`s in `dataTcOccs`. That is, when we have an `Exact` constructor name, also look for the type with same spelling. 2. Duplicate the `dataTcOccs` logic in !DsMeta. I favor (2), because code that consumes the TH AST will want the `TH.Name`s to have the right namespaces. It's really a bug that the fixity declaration above refers to a data constructor `Foo`. Going to implement (2). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9066#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler