Why Strings as Classes?

[Steven Schveighoffer]

"Denis Koroskin" wrote
> On Tue, 26 Aug 2008 23:29:33 +0400, superdan <super at dan.org> wrote:
> [snip]
>>> The D spec certainly doesn't make any guarantees about
>>> the time/memory complexity of opIndex; it's up to the implementing class
>>> to do so.
>>
>> it don't indeed. it should. that's a problem with the spec.
>>
>
> I agree. You can't rely on function invokation, i.e. the following might 
> be slow as death:
>
> auto n = collection.at(i);
> auto len = collection.length();
>
> but index operations and properties getters should be real-time and have 
> O(1) complexity by design.
>
> auto n = collection[i];
> auto len = collection.length;

less than O(n) complexity please :)  Think of tree map complexity which is 
usually O(lg n) for lookups.  And the opIndex syntax is sooo nice for maps 
:)

In general, opIndex just shouldn't imply 'linear search', as its roots come 
from array lookup, which is always O(1).  The perception is that x[n] should 
be fast.  Otherwise you have coders using x[n] all over the place thinking 
they are doing quick lookups, and wondering why their code is so damned 
slow.

-Steve