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// Copyright 2012 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview A labs location for functions destined for Closure's
* {@code goog.object} namespace.
*/
goog.provide('goog.labs.object');
/**
* Whether two values are not observably distinguishable. This
* correctly detects that 0 is not the same as -0 and two NaNs are
* practically equivalent.
*
* The implementation is as suggested by harmony:egal proposal.
*
* @param {*} v The first value to compare.
* @param {*} v2 The second value to compare.
* @return {boolean} Whether two values are not observably distinguishable.
* @see http://wiki.ecmascript.org/doku.php?id=harmony:egal
*/
goog.labs.object.is = function(v, v2) {
if (v === v2) {
// 0 === -0, but they are not identical.
// We need the cast because the compiler requires that v2 is a
// number (although 1/v2 works with non-number). We cast to ? to
// stop the compiler from type-checking this statement.
return v !== 0 || 1 / v === 1 / /** @type {?} */ (v2);
}
// NaN is non-reflexive: NaN !== NaN, although they are identical.
return v !== v && v2 !== v2;
};
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