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2.5 Balancing

Procedure: rope-balance rope ¶

If rope is unbalanced, returns a balanced rope, otherwise does nothing and returns rope itself. This procedure will not only reallocate the nodes themselves (by necessity since the data structure is immutable) but it may also reallocate the strings involved by attempting to defragment them, so it will concatenate small strings to bring their size closer to *rope-maximum-leaf-size*. It will not go in the other direction and attempt to split long leaf strings however. Long strings can only be found in a rope if the user of the API has explicitly put them there. Note that a rope may be highly fragmented but not considered unbalanced according to rope-balanced?.

One can force the rebalancing (and defragmentation) of a rope even if it is already balanced by using:

(define r …)
(rope-ec (:rope s r) s)

Example 2.6: Forcing the rebalancing of a rope.