@orca-fe/tools/lib/number.js

front-end tools

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.by = by;
exports.ceilBy = void 0;
exports.clamp = clamp;
exports.decimalLength = decimalLength;
exports.floorBy = void 0;
exports.mix = mix;
exports.roundBy = void 0;
exports.toFixedNumber = toFixedNumber;
function toFixedNumber(num, fractionDigits) {
  if (!Number.isNaN(Number(num))) {
    return Number(Number(num).toFixed(fractionDigits));
  }
  return num;
}
function decimalLength(value) {
  var str = String(value);
  var pointPosition = str.indexOf('.');
  if (pointPosition < 0) return 0;
  return str.length - pointPosition - 1;
}
function by(fn) {
  return function (divisor) {
    var offset = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
    var decimalLen = decimalLength(divisor);
    return function (num) {
      return toFixedNumber(fn((num + offset) / divisor) * divisor - offset, decimalLen);
    };
  };
}
var roundBy = exports.roundBy = by(Math.round);
var floorBy = exports.floorBy = by(Math.floor);
var ceilBy = exports.ceilBy = by(Math.ceil);

/**
 * 把一个值限制在一个上限和下限之间
 * @param _num 当前数字
 * @param lower 最小值
 * @param upper 最大值
 */
function clamp(_num, lower, upper) {
  var num = _num;
  // eslint-disable-next-line no-self-compare
  if (num === num) {
    if (upper !== undefined) {
      // 如果上限制大于number，则number的值不变，反之，number赋值upper的值
      num = num <= upper ? num : upper;
    }
    if (lower !== undefined) {
      // 同样的，如果下限值小于number，则number值不变，防止，number赋值lower的值
      num = num >= lower ? num : lower;
    }
  }
  return num;
}
function mix(x, y, _a) {
  var a = clamp(_a, 0, 1);
  return x * (1 - a) + y * a;
}