es5.js
1003 Bytes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
'use strict';
var toStr = Object.prototype.toString;
var isPrimitive = require('./helpers/isPrimitive');
var isCallable = require('is-callable');
// https://es5.github.io/#x8.12
var ES5internalSlots = {
'[[DefaultValue]]': function (O, hint) {
var actualHint = hint || (toStr.call(O) === '[object Date]' ? String : Number);
if (actualHint === String || actualHint === Number) {
var methods = actualHint === String ? ['toString', 'valueOf'] : ['valueOf', 'toString'];
var value, i;
for (i = 0; i < methods.length; ++i) {
if (isCallable(O[methods[i]])) {
value = O[methods[i]]();
if (isPrimitive(value)) {
return value;
}
}
}
throw new TypeError('No default value');
}
throw new TypeError('invalid [[DefaultValue]] hint supplied');
}
};
// https://es5.github.io/#x9
module.exports = function ToPrimitive(input, PreferredType) {
if (isPrimitive(input)) {
return input;
}
return ES5internalSlots['[[DefaultValue]]'](input, PreferredType);
};