[snprbob86]

I'd like to see a rope-variant of the 2-3 finger tree.

2-3 finger trees are immutable/persistent and support access to both ends in amortized constant time and logarithmic concatenation and splitting.

The complicating factor being that for flyweight values, like characters, the interior nodes of the tree would be prohibitive for one leaf per character. Surely there must be a variant of 2-3 finger trees that addresses this.

[jeffffff]

you can implement a rope as a 2-3 finger tree of string literals. i wrote a java implementation of 2-3 finger trees a few months ago and implemented both ropes of bytes and ropes of chars (rope backed by finger tree of java Strings here: https://github.com/jeffplaisance/fingertree/blob/master/src/...).

[microtonal]

This might be of interest:

http://hackage.haskell.org/package/rope