74 lines
1.9 KiB
JavaScript
74 lines
1.9 KiB
JavaScript
/**
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* @license Apache-2.0
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*
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* Copyright (c) 2019 The Stdlib Authors.
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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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'use strict';
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// MODULES //
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var isObject = require( '@stdlib/assert/is-object' );
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var isFunction = require( '@stdlib/assert/is-function' );
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var defineMemoizedProperty = require( './../../define-memoized-property' );
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// MAIN //
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/**
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* Defines a memoized read-only object property.
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*
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* ## Notes
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*
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* - Read-only properties are **enumerable** and **non-configurable**.
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*
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* @param {Object} obj - object on which to define the property
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* @param {(string|symbol)} prop - property name
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* @param {Function} fcn - function whose return value will be memoized and set as the property value
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* @throws {TypeError} first argument must be an object
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* @throws {TypeError} third argument must be a function
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*
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* @example
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* var obj = {};
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*
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* function foo() {
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* return 'bar';
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* }
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*
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* setMemoizedReadOnly( obj, 'foo', foo );
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*
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* var v = obj.foo;
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* // returns 'bar'
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*/
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function setMemoizedReadOnly( obj, prop, fcn ) {
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if ( !isObject( obj ) ) {
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throw new TypeError( 'invalid argument. First argument must be an object. Value: `' + obj + '`.' );
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}
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if ( !isFunction( fcn ) ) {
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throw new TypeError( 'invalid argument. Third argument must be a function. Value: `' + fcn + '`.' );
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}
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defineMemoizedProperty( obj, prop, {
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'configurable': false,
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'enumerable': true,
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'writable': false,
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'value': fcn
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});
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}
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// EXPORTS //
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module.exports = setMemoizedReadOnly;
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