Making generalized Trie type in D

[Roman D. Boiko]

On Monday, 11 June 2012 at 18:42:14 UTC, Dmitry Olshansky wrote:
> 0 ^ 0 = 1 while T.init P^ T.init == T.init :)
> other are almot the same but
> 1 ^ 1 = 0 while x P^ y == y
> So it's not symmetric when x,y != T.init for starters ;)

Just a remark that DCT no longer needs tries to be immutable, 
since I decided not to backtrack which strings affect which 
syntax elements. OTOH, it is important to be able to do updates 
and reads at any time (intermixed).

Another note is that XOR makes sense only if you plan to do 
reverse transforms, or expect to pack diffs (if they will be 
sparse). Otherwise it would be more efficient to store new values 
directly.