aaac7fed
 liuqimichale
add
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'use strict';
var hasSymbols = typeof Symbol === 'function' && typeof Symbol.iterator === 'symbol';
var isPrimitive = require('./helpers/isPrimitive');
var isCallable = require('is-callable');
var isDate = require('is-date-object');
var isSymbol = require('is-symbol');
var ordinaryToPrimitive = function OrdinaryToPrimitive(O, hint) {
if (typeof O === 'undefined' || O === null) {
throw new TypeError('Cannot call method on ' + O);
}
if (typeof hint !== 'string' || (hint !== 'number' && hint !== 'string')) {
throw new TypeError('hint must be "string" or "number"');
}
var methodNames = hint === 'string' ? ['toString', 'valueOf'] : ['valueOf', 'toString'];
var method, result, i;
for (i = 0; i < methodNames.length; ++i) {
method = O[methodNames[i]];
if (isCallable(method)) {
result = method.call(O);
if (isPrimitive(result)) {
return result;
}
}
}
throw new TypeError('No default value');
};
var GetMethod = function GetMethod(O, P) {
var func = O[P];
if (func !== null && typeof func !== 'undefined') {
if (!isCallable(func)) {
throw new TypeError(func + ' returned for property ' + P + ' of object ' + O + ' is not a function');
}
return func;
}
return void 0;
};
// http://www.ecma-international.org/ecma-262/6.0/#sec-toprimitive
module.exports = function ToPrimitive(input) {
if (isPrimitive(input)) {
return input;
}
var hint = 'default';
if (arguments.length > 1) {
if (arguments[1] === String) {
hint = 'string';
} else if (arguments[1] === Number) {
hint = 'number';
}
}
var exoticToPrim;
if (hasSymbols) {
if (Symbol.toPrimitive) {
exoticToPrim = GetMethod(input, Symbol.toPrimitive);
} else if (isSymbol(input)) {
exoticToPrim = Symbol.prototype.valueOf;
}
}
if (typeof exoticToPrim !== 'undefined') {
var result = exoticToPrim.call(input, hint);
if (isPrimitive(result)) {
return result;
}
throw new TypeError('unable to convert exotic object to primitive');
}
if (hint === 'default' && (isDate(input) || isSymbol(input))) {
hint = 'string';
}
return ordinaryToPrimitive(input, hint === 'default' ? 'number' : hint);
};
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