Created
July 18, 2018 11:41
-
-
Save pinyin/4bcfd58caa3ab0697a15f17e9b64a207 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
class NodeTree { | |
insert(node: Node): void { | |
if (this.has(node)) { | |
throw new UnexpectedStructure() // TODO | |
} | |
const getParent = (): Node | undefined => { | |
const filter: TravelFilter = candidate => candidate.contains(node) ? Travel.ACCEPT : Travel.REJECT | |
const ancestorPaths = this.DFS(document.body, filter) | |
let parentPath: Array<Node> = [] | |
for (const path of ancestorPaths) { | |
if (path.length < parentPath.length) { | |
break | |
} | |
parentPath = path | |
} | |
return parentPath[parentPath.length - 1] | |
} | |
const parent = getParent() | |
const children = new Set<Node>() | |
if (existing(parent)) { | |
this.parentMap.set(node, parent) | |
const adjacents = this.childrenMap.get(node)! | |
new Set(adjacents).forEach(adjacent => { | |
if (node.contains(adjacent)) { | |
children.add(adjacent) | |
adjacents.delete(adjacent) | |
} | |
}) | |
} | |
this.childrenMap.set(node, children) | |
} | |
ancestors(node: Node): Path { | |
const result = [] | |
for (let parent = this.parentMap.get(node); | |
existing(parent); | |
parent = this.parentMap.get(parent)) { | |
result.unshift(parent) | |
} | |
return result | |
} | |
* DFS(node: Node, filter: TravelFilter = () => Travel.ACCEPT): IterableIterator<Path> { | |
yield [node] | |
const children = this.childrenMap.get(node) | |
if (existing(children)) { | |
for (const child of children) { | |
if (filter(child) === Travel.REJECT) { | |
continue | |
} | |
for (const subpath of this.DFS(child)) { | |
const path = [child, ...subpath] | |
if (filter(child) === Travel.ACCEPT) { | |
yield path | |
} | |
} | |
} | |
} | |
} | |
children(node: Node): Set<Node> { | |
let result = this.childrenMap.get(node) | |
if (notExisting(result)) { | |
result = new Set<Node>() | |
this.childrenMap.set(node, result) | |
} | |
return result | |
} | |
has(node: Node): boolean { | |
return existing(this.childrenMap.get(node)) | |
} | |
clear(): void { | |
this.parentMap = new Map() | |
this.childrenMap = new Map([[document.body, new Set()]]) | |
} | |
private parentMap: Map<Node, Node> = new Map() | |
private childrenMap: Map<Node, Set<Node>> = new Map([[document.body, new Set()]]) | |
} | |
enum Travel { | |
ACCEPT, | |
SKIP, | |
REJECT | |
} | |
type TravelFilter = (path: Readonly<Node>) => Travel | |
type Path = Array<Node> | |
class UnexpectedStructure extends Error {} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment