mathjs/lib/esm/type/boolean.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser with support for symbolic computation, comes with a large set of built-in functions and constants, and offers an integrated solution to work with dif

import { factory } from '../utils/factory.js';
import { deepMap } from '../utils/collection.js';
var name = 'boolean';
var dependencies = ['typed'];
export var createBoolean = /* #__PURE__ */factory(name, dependencies, _ref => {
  var {
    typed
  } = _ref;
  /**
   * Create a boolean or convert a string or number to a boolean.
   * In case of a number, `true` is returned for non-zero numbers, and `false` in
   * case of zero.
   * Strings can be `'true'` or `'false'`, or can contain a number.
   * When value is a matrix, all elements will be converted to boolean.
   *
   * Syntax:
   *
   *    math.boolean(x)
   *
   * Examples:
   *
   *    math.boolean(0)     // returns false
   *    math.boolean(1)     // returns true
   *    math.boolean(-3)     // returns true
   *    math.boolean('true')     // returns true
   *    math.boolean('false')     // returns false
   *    math.boolean([1, 0, 1, 1])     // returns [true, false, true, true]
   *
   * See also:
   *
   *    bignumber, complex, index, matrix, string, unit
   *
   * @param {string | number | boolean | Array | Matrix | null} value  A value of any type
   * @return {boolean | Array | Matrix} The boolean value
   */
  return typed(name, {
    '': function _() {
      return false;
    },
    boolean: function boolean(x) {
      return x;
    },
    number: function number(x) {
      return !!x;
    },
    null: function _null(x) {
      return false;
    },
    BigNumber: function BigNumber(x) {
      return !x.isZero();
    },
    string: function string(x) {
      // try case insensitive
      var lcase = x.toLowerCase();
      if (lcase === 'true') {
        return true;
      } else if (lcase === 'false') {
        return false;
      }

      // test whether value is a valid number
      var num = Number(x);
      if (x !== '' && !isNaN(num)) {
        return !!num;
      }
      throw new Error('Cannot convert "' + x + '" to a boolean');
    },
    'Array | Matrix': typed.referToSelf(self => x => deepMap(x, self))
  });
});