I haven't had time to think about the other points in your message yet, but wanted to comment on this one: On 21 July 2005 06:32, Brian Smith wrote:
(3) It would be useful if Cabal/GHC/Hugs/etc. #defined symbols for installed packages. This would allow us to write:
module My.Program.Compat.Lib(foo1, foo2,foo3) #if __PACKAGE_foo__ >= 110 -- Is package foo-1.1 or later available? import Foo(foo1,foo2,foo3) #else
foo1 = .... foo2 = .... foo3 = ...
#endif
Absolutely - this thought also crossed my mind recently. We should agree on a convention. __PACKAGE_<name>__ seems reasonable, but what about the version number? We could adopt the same policy as __GLASGOW_HASKELL__, namely major*100+minor, and discard any futher dimensions in the version number (e.g. 1.1.1 and 1.1.2 both get __PACKAGE_foo__==101). This perhaps isn't as intuitive as it could be: people tend to write 110 when they want 101. So is there an alternate/better scheme? Cheers, Simon