Spaces:
Paused
Paused
File size: 1,975 Bytes
3401f26 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 | 'use strict';
const TREE = Symbol();
const ROOT = Symbol();
const NEXT = Symbol();
const ITERATE_FUNC = Symbol();
class TreeIterator {
constructor(tree, root, firstResult, iterateFunction) {
this[TREE] = tree;
this[ROOT] = root;
this[NEXT] = firstResult;
this[ITERATE_FUNC] = iterateFunction;
}
next() {
const tree = this[TREE];
const iterateFunc = this[ITERATE_FUNC];
const root = this[ROOT];
if (!this[NEXT]) {
return {
done: true,
value: root,
};
}
const value = this[NEXT];
if (iterateFunc === 1) {
this[NEXT] = tree._node(value).previousSibling;
}
else if (iterateFunc === 2) {
this[NEXT] = tree._node(value).nextSibling;
}
else if (iterateFunc === 3) {
this[NEXT] = tree._node(value).parent;
}
else if (iterateFunc === 4) {
this[NEXT] = tree.preceding(value, {root: root});
}
else /* if (iterateFunc === 5)*/ {
this[NEXT] = tree.following(value, {root: root});
}
return {
done: false,
value: value,
};
}
}
Object.defineProperty(TreeIterator.prototype, Symbol.iterator, {
value: function() {
return this;
},
writable: false,
});
TreeIterator.PREV = 1;
TreeIterator.NEXT = 2;
TreeIterator.PARENT = 3;
TreeIterator.PRECEDING = 4;
TreeIterator.FOLLOWING = 5;
Object.freeze(TreeIterator);
Object.freeze(TreeIterator.prototype);
module.exports = TreeIterator;
|