Component Programming in D

[jerro]

> So I think the next *big* step from here, in D3 or some other 
> D-derived
> language, would be easing the creation of ranges. For example, a
> special low-boilerplate syntax for creating bidirectional and
> random-access ranges. Or for input (or maybe even forward) 
> ranges, a
> C#-style compile-time transformation of a generator function 
> into a
> range (With input ranges, you can technically get around 
> needing source
> transformation right now in D2 using fibers, but that has too
> much runtime overhead to be used as a general solution).

I don't think we need language support in order to have an easy 
way to create random access ranges. We could have a function that 
would be used like this:

auto squares = randomAccessRange(len, (size_t i) => i * i);

This probably wouldn't have optimal performance, but wouldn't be 
horribly slow either. Another option would be to have a mixin 
that would generate all other range methods from a method that 
would provide random access to the initial (that is, before the 
first call to popFront or popBack) range and a property that 
would return the length of the initial range.