spica
Version:
Supervisor, Coroutine, Channel, select, AtomicPromise, Cancellation, Cache, List, Queue, Stack, and some utils.
100 lines (98 loc) • 2.52 kB
text/typescript
// Memory-efficient flexible list.
export class List<N extends List.Node = List.Node> {
public length = 0;
public head?: N = undefined;
public get tail(): N | undefined {
return this.head?.next;
}
public get last(): N | undefined {
return this.head?.prev;
}
public insert(node: N, before?: N): N {
assert(!node.next);
if (++this.length === 1) {
return this.head = node.next = node.prev = node;
}
assert(node !== before);
const next = node.next = before ?? this.head!;
const prev = node.prev = next.prev!;
return next.prev = prev.next = node;
}
public delete(node: N): N {
assert(node.next);
if (--this.length === 0) {
this.head = undefined;
}
else {
const { next, prev } = node;
if (node === this.head) {
this.head = next;
}
// Error if not used.
prev!.next = next;
next!.prev = prev;
}
node.next = node.prev = undefined;
return node;
}
public unshift(node: N): N {
assert(!node.next);
return this.head = this.insert(node, this.head);
}
public push(node: N): N {
assert(!node.next);
return this.insert(node, this.head);
}
public shift(): N | undefined {
if (this.length === 0) return;
return this.delete(this.head!);
}
public pop(): N | undefined {
if (this.length === 0) return;
return this.delete(this.head!.prev!);
}
public clear(): void {
this.length = 0;
this.head = undefined;
}
public *[Symbol.iterator](): Iterator<N, undefined, undefined> {
for (let node = this.head; node !== undefined;) {
yield node;
node = node.next;
if (node === this.head) break;
}
}
public flatMap<T>(f: (node: N) => ArrayLike<T>): T[] {
const acc = [];
for (let node = this.head; node !== undefined;) {
const as = f(node);
switch (as.length) {
case 0:
break;
case 1:
acc.push(as[0]);
break;
default:
for (let len = as.length, i = 0; i < len; ++i) {
acc.push(as[i]);
}
}
node = node.next;
if (node === this.head) break;
}
return acc;
}
public find(f: (node: N) => unknown): N | undefined {
for (let node = this.head; node !== undefined;) {
if (f(node)) return node;
node = node.next;
if (node === this.head) break;
}
}
}
export namespace List {
export class Node {
public next?: this = undefined;
public prev?: this = undefined;
}
}