3 ms·
If you ask for the type of (+) it's Num a => a -> a -> a So it does say something about + through its type.
by tromp 5y ago
If you ask for the type of (+) it's Num a => a -> a -> a
So it does say something about + through its type.
- ParetoOptimal 5y agoIf you presume the user knows the type of (+) which I think is kind of fair. Ideally though it would be: (+) has no instance for (Num [Integer]) The the improvement the GHC team made is already huge for those that have at least heard of Num, which I'd guess is anyone who's went through a Haskell tutorial.