They are trees, so not O(1) access or update, more like O(logn), with some memory fragmentation for every update, insertion or deletion. Tuples and binaries gi

They are trees, so not O(1) access or update, more like O(logn), with some memory fragmentation for every update, insertion or deletion. Tuples and binaries give O(1) read access, so depending on your use case, they may be better. Also look at zippers, finger trees and ropes for more dynamic use, especially local operations (cursors).