data-structure-typed/src/utils/utils.ts

/**
 * data-structure-typed
 *
 * @author Tyler Zeng
 * @copyright Copyright (c) 2022 Tyler Zeng <zrwusa@gmail.com>
 * @license MIT License
 */
import type {Thunk, ToThunkFn, TrlAsyncFn, TrlFn} from '../types';

export const uuidV4 = function () {
  return 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'.replace(/[x]/g, function (c) {
    const r = (Math.random() * 16) | 0,
      v = c == 'x' ? r : (r & 0x3) | 0x8;
    return v.toString(16);
  });
};

export const arrayRemove = function <T>(array: T[], predicate: (item: T, index: number, array: T[]) => boolean): T[] {
  let i = -1,
    len = array ? array.length : 0;
  const result = [];

  while (++i < len) {
    const value = array[i];
    if (predicate(value, i, array)) {
      result.push(value);
      Array.prototype.splice.call(array, i--, 1);
      len--;
    }
  }

  return result;
};

export const THUNK_SYMBOL = Symbol('thunk');

export const isThunk = (fnOrValue: any) => {
  return typeof fnOrValue === 'function' && fnOrValue.__THUNK__ === THUNK_SYMBOL;
};

export const toThunk = (fn: ToThunkFn): Thunk => {
  const thunk = () => fn();
  thunk.__THUNK__ = THUNK_SYMBOL;
  return thunk;
};

export const trampoline = (fn: TrlFn) => {
  const cont = (...args: [...Parameters<TrlFn>]) => toThunk(() => fn(...args));

  return Object.assign(
    (...args: [...Parameters<TrlFn>]) => {
      let result = fn(...args);

      while (isThunk(result) && typeof result === 'function') {
        result = result();
      }

      return result;
    },
    {cont}
  );
};

export const trampolineAsync = (fn: TrlAsyncFn) => {
  const cont = (...args: [...Parameters<TrlAsyncFn>]) => toThunk(() => fn(...args));

  return Object.assign(
    async (...args: [...Parameters<TrlAsyncFn>]) => {
      let result = await fn(...args);

      while (isThunk(result) && typeof result === 'function') {
        result = await result();
      }

      return result;
    },
    {cont}
  );
};

export const getMSB = (value: number): number => {
  if (value <= 0) {
    return 0;
  }
  return 1 << (31 - Math.clz32(value));
};