#9497: Silent typed holes -------------------------------------+------------------------------------- Reporter: merijn | Owner: merijn Type: feature | Status: new request | Milestone: 7.10.1 Priority: normal | Version: 7.8.3 Component: Compiler | Keywords: typed holes, Resolution: | warnings Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: | Blocked By: None/Unknown | Related Tickets: Test Case: | Blocking: | Differential Revisions: Phab:D442 | -------------------------------------+------------------------------------- Comment (by Austin Seipp <austin@…>): In [changeset:"2cc854b7133e38c7ad1107057931761782d03594/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="2cc854b7133e38c7ad1107057931761782d03594" Add -fdefer-typed-holes flag which defers hole errors to runtime. Summary: As proposed by Richard on Trac. This patch adds a new flag -fdefer-typed- holes and changes the semantics of the -fno-warn-typed-holes flag. To summarise, by default GHC has typed holes enabled and produces a compile error when it encounters a typed hole. When -fdefer-type-errors OR -fdefer-typed-holes is enabled, hole errors are converted to warnings and result in runtime errors when evaluated. The warning flag -fwarn-typed-holes is on by default. Without -fdefer- type-errors or -fdefer-typed-holes this flag is a no-op, since typed holes are an error under these conditions. If either of the defer flags are enabled (converting typed hole errors into warnings) the -fno-warn-typed-holes flag disables the warnings. This means compilation silently succeeds and evaluating a hole will produce a runtime error. The rationale behind allowing typed holes warnings to be silenced is that tools like Syntastic for vim highlight warnings and hole warnings may be undesirable. Signed-off-by: Merijn Verstraaten <merijn@inconsistent.nl> Test Plan: validate Reviewers: austin, simonpj, thomie Reviewed By: simonpj, thomie Subscribers: Fuuzetsu, thomie, carter Differential Revision: https://phabricator.haskell.org/D442 GHC Trac Issues: #9497 Conflicts: compiler/main/DynFlags.hs }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9497#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler