alexeyraspopov

// Gaussian random number generator based on Box-Muller transformation
export function* randomNormal(mu, sigma) {
  let x = null;
  let y = null;
  let s = null;

  while (true) {
    do {
      x = 2 * Math.random() - 1;
      y = 2 * Math.random() - 1;

alexeyraspopov

import React from 'react';
import { create, act } from 'react-test-renderer';
import { useDerivedState } from './useDerivedState';

function TestComponent({ value }) {
  let [state, setState] = useDerivedState(value);
  let increment = jest.fn(() => setState(state + 1));
  return <button onClick={increment}>{state}</button>;
}

alexeyraspopov

import React, { createRef, forwardRef, useLayoutEffect, useMemo } from 'react';

export let Dialog = forwardRef((props, ref) => {
  let dialogRef = useMemo(() => ref || createRef(), []);
  useLayoutEffect(
    () => {
      dialogRef.current.showModal();
    },
    [dialogRef]
  );

alexeyraspopov

function LinearScale(domain, range) {
  let scale = v => interpolate(range, normalize(domain, v));
  let inverse = v => interpolate(domain, normalize(range, v));
  return Object.assign(scale, { inverse });
}

function normalize(range, x) {
  let k = range[1] - range[0];
  let b = range[0];
  return (x - b) / k;

alexeyraspopov

function useRedux(selector = x => x, ...input) {
  // достаем стор через контекст. возможно, понадобится реактовый, без react-redux
  let store = useContext(ReduxContext);
  
  // геттер для стейта с селектором. используется в нескольких местах ниже
  let getState = () => selector(store.getState(), ...input);
  
  // локальное состояние хука, содержит результат селектора от текущего состояния стора
  let [state, setState] = useState(() => getState());
  

alexeyraspopov

// React side
let currentFiber = null;

export function useState() {
  // doing something with currentFiber
}

export function render(component) {
  currentFiber = { ... };
  let content = component();

alexeyraspopov

import React from 'react';

class Counter extends React.Component {
  constructor(props) {
    super(props);
    this.state = { counter: 0 };
    this.increment = this.increment.bind(this);
  }

  increment() {

alexeyraspopov

let ReactInternals = React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED;

function useContext(context, observedBits) {
  let dispatcher = ReactInternals.ReactCurrentOwner.currentDispatcher;
  return dispatcher.readContext(context, observedBits);
}

alexeyraspopov

import React from 'react';
import Coroutine from 'react-coroutine';
import Deferred from './Deferred.js';

export default Coroutine.create(Counter);

async function* Counter() {
  let counter = 0;
  while (true) {
    let event = new Deferred();

alexeyraspopov

import React from 'react';
import { zoom, event } from 'd3';

class Zoomable extends React.Component {
  state = { x: 0, y: 0, k: 1 };
  rootRef = React.createRef();

  zoomHandler = zoom()
    .scaleExtent([0.5, 1.5])
    .translateExtent([[0, 0], [2000, 2000]]);