#10843: Allow do blocks without dollar signs as arguments -------------------------------------+------------------------------------- Reporter: agibiansky | Owner: agibiansky Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 (Parser) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #11706 | Differential Rev(s): Phab:D1219 Wiki Page: | -------------------------------------+------------------------------------- Comment (by akio): Replying to [comment:23 rwbarton]:
I don't think parsing `f a b {-# SCC #-} d e` as `f a b ({-# SCC #-} d e)` is even an option, really, since these pragmas must be ignorable by compilers that don't understand them.
Also, I think/hope this proposal does not change the parsing of any
Agreed. program that currently parses, right? I believe this is the case, although I don't have a proof. My rough argument is: 1. This extension doesn't introduce any new conflict in the parser (shift/reduce or reduce/reduce) 2. By chasing the new grammar you can see that `do`, lambda, etc. continue to parse as a `lexp`. So if there is any change in the parsing of any currently-valid program, then it must be a result of somehow triggering an existing ambiguity in the grammar, but this seems unlikely. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10843#comment:25 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler