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