You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

210 lines
7.2 KiB

3 years ago
var GOOD_LEAF_SIZE = 200;
// :: class<T> A rope sequence is a persistent sequence data structure
// that supports appending, prepending, and slicing without doing a
// full copy. It is represented as a mostly-balanced tree.
var RopeSequence = function RopeSequence () {};
RopeSequence.prototype.append = function append (other) {
if (!other.length) { return this }
other = RopeSequence.from(other);
return (!this.length && other) ||
(other.length < GOOD_LEAF_SIZE && this.leafAppend(other)) ||
(this.length < GOOD_LEAF_SIZE && other.leafPrepend(this)) ||
this.appendInner(other)
};
// :: (union<[T], RopeSequence<T>>) → RopeSequence<T>
// Prepend an array or other rope to this one, returning a new rope.
RopeSequence.prototype.prepend = function prepend (other) {
if (!other.length) { return this }
return RopeSequence.from(other).append(this)
};
RopeSequence.prototype.appendInner = function appendInner (other) {
return new Append(this, other)
};
// :: (?number, ?number) → RopeSequence<T>
// Create a rope repesenting a sub-sequence of this rope.
RopeSequence.prototype.slice = function slice (from, to) {
if ( from === void 0 ) from = 0;
if ( to === void 0 ) to = this.length;
if (from >= to) { return RopeSequence.empty }
return this.sliceInner(Math.max(0, from), Math.min(this.length, to))
};
// :: (number) → T
// Retrieve the element at the given position from this rope.
RopeSequence.prototype.get = function get (i) {
if (i < 0 || i >= this.length) { return undefined }
return this.getInner(i)
};
// :: ((element: T, index: number) → ?bool, ?number, ?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.
RopeSequence.prototype.forEach = function forEach (f, from, to) {
if ( from === void 0 ) from = 0;
if ( to === void 0 ) to = this.length;
if (from <= to)
{ this.forEachInner(f, from, to, 0); }
else
{ this.forEachInvertedInner(f, from, to, 0); }
};
// :: ((element: T, index: number) → U, ?number, ?number) → [U]
// Map the given functions over the elements of the rope, producing
// a flat array.
RopeSequence.prototype.map = function map (f, from, to) {
if ( from === void 0 ) from = 0;
if ( to === void 0 ) to = this.length;
var result = [];
this.forEach(function (elt, i) { return result.push(f(elt, i)); }, from, to);
return result
};
// :: (?union<[T], RopeSequence<T>>) → RopeSequence<T>
// Create a rope representing the given array, or return the rope
// itself if a rope was given.
RopeSequence.from = function from (values) {
if (values instanceof RopeSequence) { return values }
return values && values.length ? new Leaf(values) : RopeSequence.empty
};
var Leaf = /*@__PURE__*/(function (RopeSequence) {
function Leaf(values) {
RopeSequence.call(this);
this.values = values;
}
if ( RopeSequence ) Leaf.__proto__ = RopeSequence;
Leaf.prototype = Object.create( RopeSequence && RopeSequence.prototype );
Leaf.prototype.constructor = Leaf;
var prototypeAccessors = { length: { configurable: true },depth: { configurable: true } };
Leaf.prototype.flatten = function flatten () {
return this.values
};
Leaf.prototype.sliceInner = function sliceInner (from, to) {
if (from == 0 && to == this.length) { return this }
return new Leaf(this.values.slice(from, to))
};
Leaf.prototype.getInner = function getInner (i) {
return this.values[i]
};
Leaf.prototype.forEachInner = function forEachInner (f, from, to, start) {
for (var i = from; i < to; i++)
{ if (f(this.values[i], start + i) === false) { return false } }
};
Leaf.prototype.forEachInvertedInner = function forEachInvertedInner (f, from, to, start) {
for (var i = from - 1; i >= to; i--)
{ if (f(this.values[i], start + i) === false) { return false } }
};
Leaf.prototype.leafAppend = function leafAppend (other) {
if (this.length + other.length <= GOOD_LEAF_SIZE)
{ return new Leaf(this.values.concat(other.flatten())) }
};
Leaf.prototype.leafPrepend = function leafPrepend (other) {
if (this.length + other.length <= GOOD_LEAF_SIZE)
{ return new Leaf(other.flatten().concat(this.values)) }
};
prototypeAccessors.length.get = function () { return this.values.length };
prototypeAccessors.depth.get = function () { return 0 };
Object.defineProperties( Leaf.prototype, prototypeAccessors );
return Leaf;
}(RopeSequence));
// :: RopeSequence
// The empty rope sequence.
RopeSequence.empty = new Leaf([]);
var Append = /*@__PURE__*/(function (RopeSequence) {
function Append(left, right) {
RopeSequence.call(this);
this.left = left;
this.right = right;
this.length = left.length + right.length;
this.depth = Math.max(left.depth, right.depth) + 1;
}
if ( RopeSequence ) Append.__proto__ = RopeSequence;
Append.prototype = Object.create( RopeSequence && RopeSequence.prototype );
Append.prototype.constructor = Append;
Append.prototype.flatten = function flatten () {
return this.left.flatten().concat(this.right.flatten())
};
Append.prototype.getInner = function getInner (i) {
return i < this.left.length ? this.left.get(i) : this.right.get(i - this.left.length)
};
Append.prototype.forEachInner = function forEachInner (f, from, to, start) {
var leftLen = this.left.length;
if (from < leftLen &&
this.left.forEachInner(f, from, Math.min(to, leftLen), start) === false)
{ return false }
if (to > leftLen &&
this.right.forEachInner(f, Math.max(from - leftLen, 0), Math.min(this.length, to) - leftLen, start + leftLen) === false)
{ return false }
};
Append.prototype.forEachInvertedInner = function forEachInvertedInner (f, from, to, start) {
var leftLen = this.left.length;
if (from > leftLen &&
this.right.forEachInvertedInner(f, from - leftLen, Math.max(to, leftLen) - leftLen, start + leftLen) === false)
{ return false }
if (to < leftLen &&
this.left.forEachInvertedInner(f, Math.min(from, leftLen), to, start) === false)
{ return false }
};
Append.prototype.sliceInner = function sliceInner (from, to) {
if (from == 0 && to == this.length) { return this }
var leftLen = this.left.length;
if (to <= leftLen) { return this.left.slice(from, to) }
if (from >= leftLen) { return this.right.slice(from - leftLen, to - leftLen) }
return this.left.slice(from, leftLen).append(this.right.slice(0, to - leftLen))
};
Append.prototype.leafAppend = function leafAppend (other) {
var inner = this.right.leafAppend(other);
if (inner) { return new Append(this.left, inner) }
};
Append.prototype.leafPrepend = function leafPrepend (other) {
var inner = this.left.leafPrepend(other);
if (inner) { return new Append(inner, this.right) }
};
Append.prototype.appendInner = function appendInner (other) {
if (this.left.depth >= Math.max(this.right.depth, other.depth) + 1)
{ return new Append(this.left, new Append(this.right, other)) }
return new Append(this, other)
};
return Append;
}(RopeSequence));
var ropeSequence = RopeSequence;
export default ropeSequence;