78 lines
2.2 KiB
JavaScript
78 lines
2.2 KiB
JavaScript
// Copyright 2009 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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* @fileoverview Useful compiler idioms.
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*
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*/
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goog.provide('goog.reflect');
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/**
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* Syntax for object literal casts.
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* @see http://go/jscompiler-renaming
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* @see http://code.google.com/p/closure-compiler/wiki/
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* ExperimentalTypeBasedPropertyRenaming
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*
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* Use this if you have an object literal whose keys need to have the same names
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* as the properties of some class even after they are renamed by the compiler.
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*
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* @param {!Function} type Type to cast to.
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* @param {Object} object Object literal to cast.
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* @return {Object} The object literal.
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*/
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goog.reflect.object = function(type, object) {
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return object;
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};
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/**
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* To assert to the compiler that an operation is needed when it would
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* otherwise be stripped. For example:
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* <code>
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* // Force a layout
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* goog.reflect.sinkValue(dialog.offsetHeight);
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* </code>
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* @type {!Function}
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*/
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goog.reflect.sinkValue = function(x) {
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goog.reflect.sinkValue[' '](x);
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return x;
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};
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/**
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* The compiler should optimize this function away iff no one ever uses
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* goog.reflect.sinkValue.
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*/
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goog.reflect.sinkValue[' '] = goog.nullFunction;
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/**
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* Check if a property can be accessed without throwing an exception.
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* @param {Object} obj The owner of the property.
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* @param {string} prop The property name.
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* @return {boolean} Whether the property is accessible. Will also return true
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* if obj is null.
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*/
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goog.reflect.canAccessProperty = function(obj, prop) {
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/** @preserveTry */
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try {
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goog.reflect.sinkValue(obj[prop]);
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return true;
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} catch (e) {}
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return false;
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};
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