On Wed, 28 Nov 2007, manu wrote:
Hello,
I'm trying to build diverse packages from Hackage with ghc 6.8.1, they usually fail to build because of missing language extensions.
Sometimes I am unable to determine the proper name of the extension missing in .cabal I tend to slap {- #OPTIONS -fglasgow-exts #-} at the top of the troublesome file. It works, but out of curiosity, what is the downside of such an approach ? (bigger executables ?)
Mistakes can slip through more easily. Things that aren't allowed in Haskell 98 are now accepted, although they might just be mistakes. E.g. when switched on glasgow-exts the compiler accepts type List = [] Although not wrong, it is not Haskell 98 and can be easily replaced by type List a = [a] I wrote definitions like the former one several times, before becoming aware that they use a language extension.