mall-front-app/unpackage/dist/dev/mp-weixin/sheep/helper/digit.js

"use strict";
function strip(num, precision = 15) {
  return +parseFloat(Number(num).toPrecision(precision));
}
function digitLength(num) {
  const eSplit = num.toString().split(/[eE]/);
  const len = (eSplit[0].split(".")[1] || "").length - +(eSplit[1] || 0);
  return len > 0 ? len : 0;
}
function float2Fixed(num) {
  if (num.toString().indexOf("e") === -1) {
    return Number(num.toString().replace(".", ""));
  }
  const dLen = digitLength(num);
  return dLen > 0 ? strip(Number(num) * Math.pow(10, dLen)) : Number(num);
}
function checkBoundary(num) {
  {
    if (num > Number.MAX_SAFE_INTEGER || num < Number.MIN_SAFE_INTEGER) {
      console.warn(`${num} 超出了精度限制，结果可能不正确`);
    }
  }
}
function iteratorOperation(arr, operation) {
  const [num1, num2, ...others] = arr;
  let res = operation(num1, num2);
  others.forEach((num) => {
    res = operation(res, num);
  });
  return res;
}
function times(...nums) {
  if (nums.length > 2) {
    return iteratorOperation(nums, times);
  }
  const [num1, num2] = nums;
  const num1Changed = float2Fixed(num1);
  const num2Changed = float2Fixed(num2);
  const baseNum = digitLength(num1) + digitLength(num2);
  const leftValue = num1Changed * num2Changed;
  checkBoundary(leftValue);
  return leftValue / Math.pow(10, baseNum);
}
function divide(...nums) {
  if (nums.length > 2) {
    return iteratorOperation(nums, divide);
  }
  const [num1, num2] = nums;
  const num1Changed = float2Fixed(num1);
  const num2Changed = float2Fixed(num2);
  checkBoundary(num1Changed);
  checkBoundary(num2Changed);
  return times(
    num1Changed / num2Changed,
    strip(Math.pow(10, digitLength(num2) - digitLength(num1)))
  );
}
function round(num, ratio) {
  const base = Math.pow(10, ratio);
  let result = divide(Math.round(Math.abs(times(num, base))), base);
  if (num < 0 && result !== 0) {
    result = times(result, -1);
  }
  return result;
}
exports.round = round;