41 lines
1.5 KiB
JavaScript
41 lines
1.5 KiB
JavaScript
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"use strict";
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// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
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// See LICENSE in the project root for license information.
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.StringBuilder = void 0;
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/**
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* This class allows a large text string to be constructed incrementally by appending small chunks. The final
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* string can be obtained by calling StringBuilder.toString().
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*
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* @remarks
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* A naive approach might use the `+=` operator to append strings: This would have the downside of copying
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* the entire string each time a chunk is appended, resulting in `O(n^2)` bytes of memory being allocated
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* (and later freed by the garbage collector), and many of the allocations could be very large objects.
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* StringBuilder avoids this overhead by accumulating the chunks in an array, and efficiently joining them
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* when `getText()` is finally called.
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*
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* @public
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*/
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class StringBuilder {
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constructor() {
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this._chunks = [];
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}
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/** {@inheritDoc IStringBuilder.append} */
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append(text) {
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this._chunks.push(text);
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}
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/** {@inheritDoc IStringBuilder.toString} */
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toString() {
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if (this._chunks.length === 0) {
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return '';
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}
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if (this._chunks.length > 1) {
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const joined = this._chunks.join('');
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this._chunks.length = 1;
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this._chunks[0] = joined;
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}
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return this._chunks[0];
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}
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}
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exports.StringBuilder = StringBuilder;
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//# sourceMappingURL=StringBuilder.js.map
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