Why is D slower than LuaJIT?

[Jonathan M Davis]

On Thursday 23 December 2010 05:22:55 spir wrote:
> On Wed, 22 Dec 2010 23:22:56 -0600
> 
> Andrei Alexandrescu <SeeWebsiteForEmail at erdani.org> wrote:
> > I'm thinking what to do about iota, which has good features but exacts
> > too much cost on tight loop performance. One solution would be to define
> > iota to be the simple, forward range that I defined as Iota2 in my
> > previous post. Then, we need a different name for the full-fledged iota
> > (random-access, has known length, iterates through the same numbers
> > forward and backward etc). Ideas?
> 
> I would keep length and add an opIn: if (e in interval) {...}. (I'm unsure
> whether it's worth allowing different types for bounds and/or for step;
> I'd rather make things simple.) Then, you could call it Interval, what do
> you think?
> 
> Note: The result would be very similar to python (x)ranges. D has a
> notation for a slightly narrower notion: '..'. Thus, what about:
> Interval!int interval = 1..9;
> or else:
> 	auto interval = Interval!int(1..9);
> ?
> 
> What kind of thingie does "i..j" actually construct as of now?

I believe that the only place that .. works is within []. If an object overrides 
an opSlice() which takes parameters, then that syntax can be used. I don't 
believe that it works on its own at all.

- Jonathan M Davis