Sha256: d539e17ca1377e2170a2ff46874b8ccbae2aef38f14dbc44ed8e60725e8453b8
Contents?: true
Size: 1.81 KB
Versions: 125
Compression:
Stored size: 1.81 KB
Contents
'use strict';
function fromTrail(tree, last) {
if (last[0] === 'left') {
return {
value: last[1],
left: tree,
right: last[2]
};
}
return {
value: last[1],
left: last[2],
right: tree
};
}
function rebuildTree(tree, trail) {
if (trail.length === 0) return tree;
var last = trail[0];
return rebuildTree(fromTrail(tree, last), trail.slice(1));
}
var Zipper = function (tree, trail) {
this.tree = tree;
this.trail = trail;
};
Zipper.fromTree = function (tree) {
return new Zipper(tree, []);
};
Zipper.prototype.toTree = function () {
return rebuildTree(this.tree, this.trail);
};
Zipper.prototype.value = function () {
return this.tree.value;
};
Zipper.prototype.left = function () {
if (!this.tree.left) return null;
return new Zipper(
this.tree.left,
[['left', this.tree.value, this.tree.right]].concat(this.trail)
);
};
Zipper.prototype.right = function () {
if (!this.tree.right) return null;
return new Zipper(
this.tree.right,
[['right', this.tree.value, this.tree.left]].concat(this.trail)
);
};
Zipper.prototype.up = function () {
if (this.trail.length === 0) return null;
var last = this.trail[0];
return new Zipper(fromTrail(this.tree, last), this.trail.slice(1));
};
Zipper.prototype.setValue = function (value) {
return new Zipper(
{
value: value,
left: this.tree.left,
right: this.tree.right
},
this.trail
);
};
Zipper.prototype.setLeft = function (left) {
return new Zipper(
{
value: this.tree.value,
left: left,
right: this.tree.right
},
this.trail
);
};
Zipper.prototype.setRight = function (right) {
return new Zipper(
{
value: this.tree.value,
left: this.tree.left,
right: right
},
this.trail
);
};
module.exports = Zipper;
Version data entries
125 entries across 125 versions & 1 rubygems