-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Ian Lynagh wrote:
* The same set of extensions is used for every module. For example, if you want to allow overlapping instances in one particular place[1] then you must allow them everywhere.
You explicitly have to add potentially dangerous extensions when you need them, that would be a gain, the downside being that you actually have to write them...
* If you want to load one of the modules in ghci, say, then you need to tell it what flags to use.
It's more or less this that raised this question at all. Big gain if you didn't have to.
Thus I propose that the .cabal file actually specifies what extensions the modules are /allowed/ to use, but does not actually enable them. They would then be enabled by LANGUAGE pragmas in the modules as necessary. So, if the .cabal file says "Extensions: E, F" then the modules will be compiled with --no-extension-flags --allowed-extension=E,F and if a module has "{-# LANGUAGE E #-}" then only extension E would be enabled for that module. If a module has "{-# LANGUAGE E,G #-}" then compilation would fail as extension G is not permitted.
Any comments? Criticisms? Flames?
Yes! It's a compiler independent way of adding extensions, yet the control of what can be used is maintained by Cabal. There will be a phase when many cabal projects has to be adapted, but it might just be worth it. I like it a lot, thanks Ian! Cheers, Lennart Kolmodin -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGBROJ4txYG4KUCuERAhgSAKC0vYn1QnbvlxGu7raliWCXup2y9QCdEZTv 8lubE63mxDkZ2Guwyg8Vlrk= =hTWC -----END PGP SIGNATURE-----