On Sat, 2012-10-06 at 18:25 +0200, José Lopes wrote:
OK.
But, wouldn't it be possible for xmobar to use mtl-2.0.1.0 and for parsec to use mtl-2.1.1, while xmobar would use this parsec version? In this case, I am assuming that mtl-2.0.1.0 and mtl-2.1.1 are considered two different libraries.
Usually it leads to "strange" compilation errors. E.g. Package A: data AA = AA String func0 :: Int -> AA func0 n = AA $ replicate n "A" func1 :: AA -> Int func1 (AA str) = length str Package B: import A func2 :: AA -> Int func2 aa = func1 + 1 Package C: import A import B func3 :: Int -> Int func3 n = func2 $ func0 n If C and B are compiled with different versions of C, then func3 will not compile. Compiler will say that AA returned by func0 doesn't match AA expected by func2 More real examples: http://stackoverflow.com/questions/11068272/acid-state-monadstate-instance-f... http://stackoverflow.com/questions/12576817/couldnt-match-expected-type-with...
Thanks, José