70 lines
1.9 KiB
JavaScript
70 lines
1.9 KiB
JavaScript
|
'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;
|