multiple-item traversal ranges

[bearophile]

Jonathan M Davis:

> Andrei is currently against making range-based functions work with opApply 
> because of the resulting increase complexity of the implementations. They were 
> really meant for ranges, not opApply. That doesn't necessarily mean that it's 
> a guaranteed "we don't want to do it," but it's definitely questionable.

There is no "perfect design" here. I have suggested a compromise, where few basic functions (array(), walkLength()) work with every kind of iterable. Othrwise opApply becomes a third-class functionality and users need to write their own opApply-related functions.

Bye,
bearophile