D2 Short list -- opSlice

[Don]

Steven Schveighoffer wrote:
> On Thu, 19 Nov 2009 03:53:51 -0500, Don <nospam at nospam.com> wrote:
> 
>> Andrei Alexandrescu wrote:
>>> We're entering the finale of D2 and I want to keep a short list of 
>>> things that must be done and integrated in the release. It is clearly 
>>> understood by all of us that there are many things that could and 
>>> probably should be done.
>>>  1. Currently Walter and Don are diligently fixing the problems 
>>> marked on the current manuscript.
>>>  2. User-defined operators must be revamped.
>>
>> Should opIndex and opSlice be merged?
>> This would be simpler, and would allow multi-dimensional slicing.
>> Probably the simplest way to do this would be to use fixed length 
>> arrays   of length 2 for slices.
>> So, for example, if the indices are integers, then
>> opIndex(int x) { } is the 1-D index, and
>> opIndex(int[2] x) {} is a slice from x[0] to x[1],
>> which exactly corresponding to the current opSlice(x[0]..x[1]).
> 
> I hope you still mean to allow arguments other than int.

Read it.
"So, _for example_, if the indices are integers,".

> Also, how does this work with Andrei's "opBinary" proposal?

I don't know -- I'm not proposing a solution to the 
indexing-and-slicing-expression issues. Still, combining indexing and 
slicing helps a little. But I don't yet know if the opBinary concept 
will work.

I think the problem of verbosity in operator overloads (opAdd, opMul, 
... all being nearly the same) is very unimportant and shouldn't be the 
focus of attention. Two things matter:
(1) expressivity; and
(2) performance.
If you don't have these two, your verbosity will be shot to pieces anyway.
This proposal, together with opDollar(), closes the last remaining 
element of (1).