Re: [GHC] #15527: TypeApplications error message doesn't parenthesize infix name

#15527: TypeApplications error message doesn't parenthesize infix name -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 Resolution: | Keywords: | TypeApplications Operating System: Unknown/Multiple | Architecture: Type of failure: Poor/confusing | Unknown/Multiple error message | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D5071 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Krzysztof Gogolewski ): In [changeset:"5238f204482ac7f05f4e2d2e92576288cc00d42d/ghc" 5238f204/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="5238f204482ac7f05f4e2d2e92576288cc00d42d" Fix #15527 by pretty-printing an RdrName prefixly Summary: When `(.) @Int` is used without enabling `TypeApplications`, the resulting error message will pretty-print the (symbolic) `RdrName` `(.)`. However, it does so without parenthesizing it, which causes the pretty-printed expression to appear as `.@Int`. Yuck. Since the expression in a type application will always be prefix, we can fix this issue by using `pprPrefixOcc` instead of plain ol' `ppr`. Test Plan: make test TEST=T15527 Reviewers: bgamari, monoidal, simonpj Reviewed By: monoidal, simonpj Subscribers: rwbarton, carter GHC Trac Issues: #15527 Differential Revision: https://phabricator.haskell.org/D5071 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15527#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler