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# rope-sequence
This module implements a single data type, `RopeSequence`, which is a
persistent sequence type implemented as a loosely-balanced
[rope](https://www.cs.rit.edu/usr/local/pub/jeh/courses/QUARTERS/FP/Labs/CedarRope/rope-paper.pdf).
It supports appending, prepending, and slicing without doing a full
copy. Random access is somewhat more expensive than in an array
(logarithmic, with some overhead), but should still be relatively
fast.
Licensed under the MIT license.
## class `RopeSequence<T>`
`static `**`from`**`(?union<[T], RopeSequence<T>>) → RopeSequence<T>`
Create a rope representing the given array, or return the rope itself
if a rope was given.
`static `**`empty`**`: RopeSequence<T>`
The empty rope.
**`length`**`: number`
The length of the rope.
**`append`**`(union<[T], RopeSequence<T>>) → RopeSequence<T>`
Append an array or other rope to this one, returning a new rope.
**`prepend`**`(union<[T], RopeSequence<T>>) → RopeSequence<T>`
Prepend an array or other rope to this one, returning a new rope.
**`slice`**`(from: ?number = 0, to: ?number = this.length) → RopeSequence<T>`
Create a rope repesenting a sub-sequence of this rope.
**`get`**`(index: number) → T`
Retrieve the element at the given position from this rope.
**`forEach`**`(f: fn(element: T, index: number) → ?bool, from: ?number, to: ?number)`
Call the given function for each element between the given indices.
This tends to be more efficient than looping over the indices and
calling `get`, because it doesn't have to descend the tree for every
element.
`to` may be less then `from`, in which case the iteration will happen
in reverse (starting at index `from - 1`, down to index `to`.
The iteration function may return `false` to abort iteration early.
**`map`**`(f: fn(element: T, index: number) → U, from: ?number, to: ?number) → [U]`
Map the given functions over the elements of the rope, producing a
flat array.
**`flatten`**`() → [T]`
Return the content of this rope as an array.