[RFC] Add an operator for ranges to D. Pros and cons?

[bearophile]

Dejan Lekic:

> Dear D community, I do not know about You, but I certainly do 
> not like writing code like:
>
> inRange.fooRange(param).barRange.
>   .bazRange(param1, param2).outRange;

I suggest to format it this way, it's more readable:

auto something = inRange
                  .fooRange(param)
                  .barRange()
                  .bazRange(param1, param2)
                  .outRange();


> Therefore I would like to know what do you think about the idea 
> of having additional operator exclusively made for ranges? This 
> operator would make it obvious that data are "streamed" (lack 
> of better term) among ranges.
>
> The first name I could come up with was "opArrow" but "opData" 
> could also be okay, and operator would be either "~>" or "->".
>
> This would give us an obvious, unambiguous statement:
>
> Console.in ~> filter1(param) ~> fooRange ~> Console.out;
> // Console is an imaginary class/struct

I think it doesn't give a significant improvement. But maybe
there are more interesting use cases.

I'd like D ranges to support the "~" (using a template mixin to
give them such operator), that acts like chain. So instead of
writing:

range1.chain(range2)

You write:

range1 ~ range2

It's also nice to have lazy lists, maybe based on fibers, with
few operators to concat them, etc.

Bye,
bearophile