On Mon, Dec 12, 2011 at 9:23 AM, Carl Howells <chowells79@gmail.com> wrote:

> There is absolutely no implication of consuming anything in the definitions
> of many or some. This is how they happen to behave when used in the context
> of some parsing libraries, but that's all. If many or some always go into an
> infinite loop for some Alternative instance, then I suspect that the
> instance itself is either broken or shouldn't exist.

So, then... The instance for Maybe shouldn't exist?

Don't be silly. The purpose of some and many is to be used with combinators that are expected to fail sometimes. If you use them with combinators that always succeed, of course you're going to get an infinite loop. Would you propose to ban recursive functions because they might not terminate?

Apparently the confusion here lies with the fact that the documentation for some and many are too terse for their behaviour to be easily understood. That's a whole different category of problem than "ban them!".