merkle reverse

[SimonN]

On Thursday, 5 April 2018 at 09:49:58 UTC, Seb wrote:
> Strings are bi-directional ranges, but they aren't 
> random-access nor have a length
> chunks requires hasSlicing + hasLength:

Okay, thanks for the great references. chunks/slide certainly 
need the length to decide which, and how many, elements to serve 
in the final chunk. The crucial part is now that an autodecoded 
string's final element can be determined in O(1) by looking at up 
to 4 code units from its un-decoded end, whereas its autodecoded 
length cannot be found in O(1).

-- Simon