range and algorithm-related stuff

[bearophile]

Andrei Alexandrescu:
You can take a look at my dlibs, they may give you ideas, because contain all such lazy functions and some more.

I presume you have chosen to not tell apart the lazy functions from the eager ones.


> 2. take(n, range) => takes at most n elements out of a range (very 
> useful with infinite ranges!)

I think that an xslice is better than an xtake (it's essentially a lazy version of a more powerful version of the slicing that in D you can do on arrays).

Bye,
bearophile