#10331: Accept HsSyn in splices and generate it in quotes (ghc-api) -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: feature | Status: new request | Milestone: Priority: low | Version: 7.11 Component: Template | Operating System: Unknown/Multiple Haskell | Type of failure: None/Unknown Keywords: | Blocked By: Architecture: | Related Tickets: Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- I propose a language pragma `GhcTemplateHaskell`, which, when enabled, causes Template Haskell splices to accept `HsSyn` return values, and causes TH quotes to return `HsSyn` trees. Users of `GhcTemplateHaskell` would stop using the `template-haskell` library and just directly manipulate the frontend ASTs using the `ghc-api`. Given our ghc-api track record, you would probably not be able to write code using this without having it break every GHC release. However, clients who are willing to track GHC development would reap the following benefits: 1. All syntax in Haskell would be supported in quotes; the AST would never lag behind. Additionally, you could use the ghc-api parser to parse Haskell code to be returned in a splice. (#2041) 2. Locations from quoting would be preserved. (Problem 2 of #10330) I don't think this would be difficult to implement, but it definitely could be a ball of wax. I broke this proposal off from #2041. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10331 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler