#8809: Prettier error messages? -------------------------------------+------------------------------------- Reporter: joelteon | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): #8809,#10073,#10179 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by niteria): I've run into this while trying to hack together something like http://gcc.godbolt.org/, but for Haskell, with Core, Stg, Cmm and Asm output. With `-g` all the location data is already nicely tracked all the way to Asm and the only piece missing is a way to pretty print with some annotations about the ranges. I took a stab at adding a parameter to `Doc`, but I haven't gone through with it because [https://phabricator.haskell.org/diffusion/GHC/browse/master/compiler/main/Er... some other types] use it transitively and I couldn't decide between `SDoc a` and `SDoc Void` there. [http://hackage.haskell.org/package/pretty-1.1.3.2/docs/Text-PrettyPrint- Annotated.html pretty] appears to be the same library GHC uses and as pointed out by bgamari already supports annotations. Does anyone know if they diverged in functionality/semantics? If not, would it be a useful step to migrate GHC's `Doc` to annotated version? I think an argument against it is that it doesn't have a `Monad` instance, but I don't immediately see the benefit of having it. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8809#comment:19 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler