Paul Rubin wrote: > Chris Angelico <ros...@gmail.com> writes: >> So since you can set something to Nothing regardless of type, and >> compare it against Nothing regardless of type, it doesn't really much >> matter that there are different types of Nothing. Right? > > No that's not how type inference works. If you have x = Nothing and > pass it to a function that takes a Maybe Int, type inference means the > compiler figures out that x must have type Maybe Int. If you then also > pass x to something that takes Maybe String, you are telling the > compiler that x has two different types at the same time, so the > compiler reports a type error.
No apples and no oranges aren't the same thing, but if somebody is expecting no apples, and I give them no oranges instead, it would be churlish for them to complain that none of them are the wrong kind of fruit. -- Steve -- https://mail.python.org/mailman/listinfo/python-list
