Jonathan Cast wrote:
On Fri, 2008-10-03 at 20:43 +0100, Andrew Coppin wrote:
OK. So it's broken "for compatibility" then? (Presumably any time you change something from the Prelude, mass breakage ensues!)
I'm not a big fan of backward-compatibility myself, but changing Monad to be a sub-class of Applicative actually would have broken every monad instance in existence (at the time Applicative was added, since it didn't have any instances yet). I don't know what proportion of Haskell programs/libraries/etc. have at least one Monad instance in them, but I would guess it's high.
Hmm, that's quite a lot of breakage. So if it had been set up this way from day 1, we wouldn't be having this conversation, but it's now too expensive to change it. Is that basically what it comes down to?