Making generalized Trie type in D

[Dmitry Olshansky]

On 05.06.2012 2:28, Roman D. Boiko wrote:
> On Monday, 4 June 2012 at 22:21:42 UTC, Dmitry Olshansky wrote:
>> And you can fake immutability, buy always picking up an unused slot
>> btw. No need to go beyond logical immutability.
> That's applicable in some cases, not in general. But I agree that often
> it is possible to optimize if use cases are known.
>
> My example concern was about fundamental problem of range APIs for
> immutable data structures, which is not possible to emulate: popFront is
> mutating by design.

Keep in mind Ranges are temporary object most of the time. They are 
grease for wheels of algorithms. Given data structure S, it's  range is 
R(element of S). Thus for immutable data structure range will be mutable 
entity of immutable element type.

Interesting example is immutable strings, that still have ranges over 
them, that even return dchar not an immutable(char).

-- 
Dmitry Olshansky