Are iterators and ranges going to co-exist?

[bearophile]

Peter Alexander:

> and you've also increased the amount of data you need to pass 
> into the function by 33%, violating the "Don't pay for what you 
> don't use" philosophy.

The "Don't pay for what you don't use" is a C++ rule, it's not a 
D Zen rule. In D you sometimes pay a little if it gives back 
enough safety or convenience elsewhere. In D there are usually 
ways to not pay, but you have to ask for it explicitly.


> Ranges are brilliant, and maybe you could even call them a 
> superset of iterators, but just like we have vectors despite 
> having matrices, and points despite having lines, we still want 
> iterators even though we have ranges. They are simply different 
> things.

There is also a price to pay if you want both abstractions in 
Phobos. A single abstraction makes things simpler, more 
compatible with each other, etc. Example: D has opApply, but at 
the moment nearly nothing in Phobos supports opApply (array() and 
foreachType, I'd like a third Phobos thing to support it).

Bye,
bearophile