Making generalized Trie type in D

[Roman D. Boiko]

On Tuesday, 5 June 2012 at 13:27:12 UTC, Roman D. Boiko wrote:
> maybe it is better to avoid immutability... or do bulk ins /del 
> before  copy.
Would it be difficult to introduce two optimizations:
* have strings of all lengths above configurable threshold go to 
the same bucket (is it reasonable?)
* have ability to store a checkpoint, then do a series of 
modifications, and store another checkpoint but reuse data which 
have not been affected.

For the second optimization a possible design would be to store 
internal state as snapshot + diffs, and apply diffs when creating 
another snapshot. Diff format should allow efficiently performing 
trie interface operations.