2011/10/5 Simon Peyton-Jones <simo...@microsoft.com>: > | In the spirit of "don't let the perfect be the enemy of the good" > | though, I'm solidly in favor of the original proposal as it is. > > This is my thought too. George is proposing to extend Haskell's existing > mechanism for numeric literals (namely, replace 4 by (fromInteger > (4::Integer))), so that it works for lists, just as Lennart did for Strings. > One could do more, as Yitz has suggested, but that would be an altogether > bigger deal, involving Template Haskell and quite a bit of new design; and if > done should apply uniformly to numeric and string literals too. > > So personally I favour George's general approach as a first step. But here > is one thought. In the spirit of monad comprehensions, should we not treat > [a,b,c] > as short for > return a `mappend` return b `mappend` return c > so that [a,b,c] syntax is, like [ e | x <- xs ] syntax, just short for > monadic goop. Then we would not need a new class at all, which would be nice.
No, you should not. Most of the types of interest (Sets, Maps, arrays) are not monads. Conflating list comprehensions with monads is a huge mistake, and this would repeat it. -Jan _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
