#478: allow comments on any line, don't require '.' for blank lines ----------------------------+----------------------------------------------- Reporter: duncan | Owner: Type: enhancement | Status: new Priority: normal | Milestone: Cabal-1.8 Component: Cabal library | Version: 1.6.0.1 Severity: normal | Resolution: Keywords: | Difficulty: unknown Ghcversion: | Platform: ----------------------------+----------------------------------------------- Comment (by duncan): Replying to [comment:2 creswick]:
The error output for this could at least mention that comments aren't allowed at the end of lines.
This is tricky because we do not know they are there.
There is also an inconsistency in the syntax for build-depends and some other lists (eg: extra-source-files). Comments at the end of a line in an extra-source-files list do not cause a parse error, yet they do when added to the end of a line in a build-depends list.
It's not actually inconsistent. Remember that "-- blah" in a field is considered as part of the field. So for build-depends, that does not parse, but it's perfectly ok to have a source file called "--" and "blah". Of course it will fail when trying to sdist because the files do not exist.
In my opinion, the simplest solution is to require that -- be escaped. (eg: \-\-, or \-- ) when it is not used as a comment delimiter.
That's fairly ugly and will not reduce confusion because people will not know that they can or should use that syntax. As I mention in the original description, I think the thing to do is to consider whether allowing "-- " as the start of a comment could possibly cause problems in fields like ghc-options, since "--" is a valid value to pass to a program. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/478#comment:3 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects