#12249: Template Haskell top level scoping error -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
But why do we want this behavior?
Consider the code in the Description. It seems perfectly reasonable to me; the two quasiquotes both bind 'x' but in each case it's clear what binds the occurrence of `x` on the RHS of `f1`, `f2`. I'm thinking of splices that generate a wad of code that needs some auxiliary bindings; we don't want to have to worry about a clash if we happen to re-use the same name when generating the auxiliary bindings in a different splice. For example, `deriving` code. In fact it's this that is causing #12245, although that code is generated by GHC itself, not by TH, but it's the same idea. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12249#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler