d3/common/utils.ts

import { assert, assertEquals, assertInstanceOf } from "https://deno.land/std@0.221.0/assert/mod.ts";
import * as path from "https://deno.land/std@0.221.0/path/mod.ts";
import { TextLineStream } from "https://deno.land/std@0.221.0/streams/mod.ts";
import { z, ZodType } from "https://deno.land/x/zod@v3.22.4/mod.ts";

export function parsed_stream<T>(parser: ZodType<T>) {
	return async function* (readable: ReadableStream<Uint8Array>) {
		const line_stream = readable
			.pipeThrough(new TextDecoderStream())
			.pipeThrough(new TextLineStream());
		for await (const line of line_stream) yield parser.parse(JSON.parse(line));
	};
}

export function serialized_stream<T>(generator: AsyncIterable<T>) {
	return async function (writable: WritableStream<Uint8Array>) {
		const stream = new TextEncoderStream();
		stream.readable.pipeTo(writable);
		for await (const item of generator) {
			const writer = stream.writable.getWriter();
			await writer.write(JSON.stringify(item) + "\n");
			writer.releaseLock();
		}
	};
}

export type Consumer<T> = (item: T) => void;

// deno-lint-ignore no-explicit-any
export type ParserOutput<T extends () => ZodType<any, any, any>> = z.infer<ReturnType<T>>;

export type PromiseSplit<T> = ReturnType<typeof split_promise<T>>;
export function split_promise<T>() {
	let resolver_ = null as Consumer<T> | null;
	const promise = new Promise<T>((r) => {
		resolver_ = r;
	});
	assert(resolver_ !== null);
	const resolver = resolver_ as Consumer<T>;
	return { promise, resolver };
}

export class AsyncQueue<T> {
	private items = [] as T[];
	private awaiting = [] as Consumer<void>[];

	public push(item: T) {
		this.items.push(item);
		const [first] = this.awaiting.splice(0, 1);
		if (first !== undefined) first();
	}

	public async pull() {
		let first = this.take_first_item();
		if (first !== undefined) return first;
		const { promise, resolver } = split_promise<void>();
		this.awaiting.push(resolver);
		await promise;
		first = this.take_first_item();
		assert(first !== undefined);
		return first as T;
	}

	private take_first_item() {
		const [first] = this.items.splice(0, 1);
		return first as T | undefined;
	}
}

export function channel<T>() {
	const queue = new AsyncQueue<T>();
	return [new Sender(queue), new Receiver(queue)] as const;
}

export function channel_generator<T>(generator: AsyncIterable<T>) {
	const [sender, receiver] = channel();
	(async () => {
		for await (const item of generator) sender.send(item);
	})();
	return receiver;
}

export class Sender<T> {
	queue;

	public constructor(queue: AsyncQueue<T>) {
		this.queue = queue;
	}

	public send(item: T) {
		this.queue.push(item);
	}

	public async send_all(iter: AsyncGenerator<T>) {
		for await (const item of iter) this.send(item);
	}
}

export class Receiver<T> {
	queue;

	public constructor(queue: AsyncQueue<T>) {
		this.queue = queue;
	}

	public async receive() {
		return await this.queue.pull();
	}

	public async *iter() {
		while (true) yield this.receive();
	}
}

export function range(from: number, to: number) {
	return new Range(from, to);
}

export class Range {
	from;
	to;

	constructor(from: number, to: number) {
		this.from = from;
		this.to = to;
	}

	includes(n: number) {
		return (n >= this.from) && (n < this.to);
	}

	[Symbol.iterator]() {
		let index = this.from;
		const to = this.to;
		return (function* () {
			while (index < to) yield index++;
		})();
	}
}

export async function launch_caught<T>(
	operation: () => Promise<T> | T,
	handler: null | ((error: unknown) => void) = null,
) {
	try {
		return await operation();
	} catch (error) {
		if (handler !== null) handler(error);
		else console.error("Lanched Uncaught :", error);
	}
}

export function log_from(meta: ImportMeta) {
	return function (...args: unknown[]) {
		const mod = path.basename(new URL(meta.url).pathname);
		console.log(`[${mod}]`, ...args);
	};
}

export class Vec2 {
	private x_;
	private y_;

	public constructor(x: number, y: number) {
		this.x_ = Math.round(x);
		this.y_ = Math.round(y);
	}

	public x() {
		return this.x_;
	}

	public y() {
		return this.y_;
	}

	public scale(factor: number) {
		return new Vec2(this.x_ * factor, this.y_ * factor);
	}

	public neg() {
		return this.scale(-1);
	}

	public add(other: Vec2) {
		return new Vec2(this.x_ + other.x_, this.y_ + other.y_);
	}

	public sub(other: Vec2) {
		return this.add(other.neg());
	}

	public inside(min: Vec2, max: Vec2) {
		if (!range(min.x(), max.x()).includes(this.x())) return false;
		if (!range(min.y(), max.y()).includes(this.y())) return false;
		return true;
	}

	public eq(other: Vec2) {
		return (this.x() === other.x()) && (this.y() === other.y());
	}

	public neq(other: Vec2) {
		return !this.eq(other);
	}

	public len() {
		return Math.sqrt(this.x() ** 2 + this.y() ** 2);
	}

	public distance(other: Vec2) {
		return this.sub(other).len();
	}

	public overlaps(other: Vec2) {
		return this.distance(other) < 1;
	}

	public clone() {
		return new Vec2(this.x(), this.y());
	}

	public normalize() {
		return new Vec2(clamp(this.x(), -1, 1), clamp(this.y(), -1, 1));
	}
}

export function clamp(x: number, min: number, max: number) {
	return Math.max(min, Math.min(x, max));
}

export function v2(x: number, y: number) {
	return new Vec2(x, y);
}

export function* enumerate<T>(iterator: Iterable<T>) {
	let index = 0;
	for (const item of iterator) yield [index++, item] as [number, T];
}

export function* chunks<T>(iterator: Iterable<T>, size: number) {
	let current = [];
	for (const item of iterator) {
		current.push(item);
		if (current.length < size) continue;
		yield current;
		current = [];
	}
}

Deno.test("test_chunk", () => {
	assertEquals(
		[...chunks([1, 2, 3, 4, 5, 6, 7], 3)],
		[[1, 2, 3], [4, 5, 6]],
	);
});

export function wait(ms: number) {
	return new Promise((res) => setTimeout(res, ms));
}

export async function run(cmd: string, ...args: string[]) {
	const command = new Deno.Command(cmd, { args, stdin: "inherit", stdout: "piped" });
	const output = await command.output();
	if (!output.success) throw new Error();
	return new TextDecoder().decode(output.stdout);
}

export type Prototyped<P = unknown> = { constructor: { prototype: P } };
// deno-lint-ignore no-explicit-any
export type Constructible<I = unknown> = new (...args: any[]) => I;
export class ClassMap<B = unknown> {
	private inner;

	constructor() {
		this.inner = new Map();
	}

	insert<V extends Prototyped & B>(object: V) {
		const prototype = object.constructor.prototype;
		if (this.inner.has(prototype)) throw new Error();
		this.inner.set(prototype, object);
	}

	get<I extends B, C extends Constructible<I>>(class_: C) {
		const value = this.inner.get(class_.prototype);
		if (value === undefined) return null;
		assertInstanceOf(value, class_);
		return value;
	}

	has<I extends B, C extends Constructible<I>>(class_: C) {
		return this.inner.has(class_.prototype);
	}
}

Deno.test("test_classmap", () => {
	{
		class Truc {}
		class Machin {}
		class Chose {}

		const map = new ClassMap();
		const truc = new Truc();
		map.insert(truc);
		const machin = new Machin();
		map.insert(machin);

		assert(map.get(Truc) === truc);
		assert(map.get(Machin) !== truc);
		assert(map.get(Machin) === machin);
		assert(map.get(Chose) === null);
	}
	{
		interface Machinable {
			machin(): number;
		}
		// deno-lint-ignore no-unused-vars
		class Truc {}
		class Machin implements Machinable {
			machin = () => 35;
		}
		const map = new ClassMap<Machinable>();
		map.insert(new Machin());
		// map.insert(new Truc()); // note : Fails with improper typing.

		map.get(Machin);
		// map.get(Truc); // note : Fails with improper typing.
	}
});

export function maybe<T>(item: T) {
	return item as T | undefined;
}

export type Awaitable<T = unknown> = T | Promise<T>;

export function first<T>(iter: Iterable<T>) {
	for (const item of iter) return item;
	return null;
}

export function take_n<T>(iter: Iterable<T>, n: number) {
	const result = [] as T[];
	for (const item of iter) {
		if (result.length >= n) break;
		result.push(item);
	}
	return result;
}

export function* line(from: Vec2, to: Vec2) {
	let current = from.clone();
	while (current.neq(to)) {
		yield current;
		if (current.x() - to.x() > 0.5) current = current.sub(v2(1, 0));
		if (current.x() - to.x() < -0.5) current = current.add(v2(1, 0));
		if (current.y() - to.y() > 0.5) current = current.sub(v2(0, 1));
		if (current.y() - to.y() < -0.5) current = current.add(v2(0, 1));
	}
}

export function* spiral(origin: Vec2) {
	yield origin;
	for (const i of range(0, 999)) {
		const size = i * 2 + 1;
		const corner_A = origin.add(v2(-size / 2, -size / 2));
		const corner_B = origin.add(v2(size / 2, -size / 2));
		const corner_C = origin.add(v2(size / 2, size / 2));
		const corner_D = origin.add(v2(-size / 2, size / 2));
		yield* line(corner_A, corner_B);
		yield* line(corner_B, corner_C);
		yield* line(corner_C, corner_D);
		yield* line(corner_D, corner_A);
	}
}

// Deno.test("test_spiral", () => {
// //  2 | 10 11 12 13 14
// //  1 | 25  2  3  4 15
// //  0 | 24  9  1  5 16
// // -1 | 23  8  7  6 17
// // -2 | 22 21 20 19 18
// // ---+---------------
// //      -2 -1  0  1  2
// 	const result = [...take_n(spiral(v2(0, 0)), 25)];
// 	const expects = [
// 		v2(0, 0),
// 		v2(1, 1),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 		v2(),
// 	]
// });