util-helpers/lib/utils/math.util.js

一个基于业务场景的工具方法库

'use strict';

var ut2 = require('ut2');
var devWarn = require('./devWarn.js');

var radixReg = /^[-+]?0[b|o|x]\d+/i;
var dotNumberStringReg = /^\.\d+/;
function transformEffectiveNumber(value) {
    var ret;
    if (ut2.isString(value)) {
        ret = value.trim();
        if (ret === '') {
            ret = Number(ret);
        }
        else if (radixReg.test(ret) || dotNumberStringReg.test(ret)) {
            ret = ut2.toNumber(ret);
        }
        else if (ut2.isNaN(Number(ret))) {
            ret = Number.NaN;
        }
    }
    else if (ut2.isSymbol(value)) {
        ret = Number.NaN;
    }
    else if (!ut2.isNumber(value)) {
        ret = Number(value);
    }
    else {
        ret = value;
    }
    if (ut2.isNaN(ret)) {
        return Number.NaN;
    }
    return ret;
}
function isScientificNumber(num) {
    return /\d+\.?\d*e[+-]*\d+/i.test(num);
}
function strip(num, precision) {
    if (precision === void 0) { precision = 12; }
    return +parseFloat(num.toPrecision(precision));
}
function digitLength(num) {
    var eSplit = num.toString().split(/e/i);
    var len = (eSplit[0].split('.')[1] || '').length - +(eSplit[1] || 0);
    return len > 0 ? len : 0;
}
function float2Fixed(num) {
    var strNum = String(num);
    if (!isScientificNumber(strNum)) {
        return Number(strNum.replace('.', ''));
    }
    var dLen = digitLength(num);
    return dLen > 0 ? strip(+num * Math.pow(10, dLen)) : +num;
}
function checkBoundary(num) {
    if (+num > ut2.MAX_SAFE_INTEGER || +num < ut2.MIN_SAFE_INTEGER) {
        devWarn("".concat(num, " is beyond boundary when transfer to integer, the results may not be accurate"));
    }
}
function trimLeftZero(num) {
    var reg = /^([+-])?(0+)([0-9.]+)$/;
    var result = reg.exec(num);
    var sign;
    if (result) {
        sign = result[1] || '';
        return sign + (result[3][0] === '.' ? '0' + result[3] : result[3]);
    }
    return num;
}

exports.checkBoundary = checkBoundary;
exports.digitLength = digitLength;
exports.float2Fixed = float2Fixed;
exports.isScientificNumber = isScientificNumber;
exports.strip = strip;
exports.transformEffectiveNumber = transformEffectiveNumber;
exports.trimLeftZero = trimLeftZero;