forked from zhurui/management
46 lines
1.2 KiB
JavaScript
46 lines
1.2 KiB
JavaScript
|
'use strict';
|
||
|
|
|
||
|
|
var toStr = Object.prototype.toString;
|
||
|
|
|
||
|
|
var isPrimitive = require('./helpers/isPrimitive');
|
||
|
|
|
||
|
|
var isCallable = require('is-callable');
|
||
|
|
|
||
|
|
// http://ecma-international.org/ecma-262/5.1/#sec-8.12.8
|
||
|
|
var ES5internalSlots = {
|
||
|
|
'[[DefaultValue]]': function (O) {
|
||
|
|
var actualHint;
|
||
|
|
if (arguments.length > 1) {
|
||
|
|
actualHint = arguments[1];
|
||
|
|
} else {
|
||
|
|
actualHint = 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');
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
// http://ecma-international.org/ecma-262/5.1/#sec-9.1
|
||
|
|
module.exports = function ToPrimitive(input) {
|
||
|
|
if (isPrimitive(input)) {
|
||
|
|
return input;
|
||
|
|
}
|
||
|
|
if (arguments.length > 1) {
|
||
|
|
return ES5internalSlots['[[DefaultValue]]'](input, arguments[1]);
|
||
|
|
}
|
||
|
|
return ES5internalSlots['[[DefaultValue]]'](input);
|
||
|
|
};
|