48 lines
1.2 KiB
JavaScript
48 lines
1.2 KiB
JavaScript
/**
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* @license Apache-2.0
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*
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* Copyright (c) 2021 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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// MAIN //
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/**
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* Returns a regular expression to match a UTF-16 unpaired surrogate.
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*
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* @returns {RegExp} regular expression
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*
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* @example
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* var RE_UTF16_UNPAIRED_SURROGATE = reUtf16UnpairedSurrogate();
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*
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* var bool = RE_UTF16_UNPAIRED_SURROGATE.test( '\uD800' );
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* // returns true
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*
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* bool = RE_UTF16_UNPAIRED_SURROGATE.test( '\uDC00' );
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* // returns true
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*
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* bool = RE_UTF16_UNPAIRED_SURROGATE.test( 'abc' );
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* // returns false
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*/
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function reUtf16UnpairedSurrogate() {
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return /(?:[^\uD800-\uDBFF]|^)[\uDC00-\uDFFF]|[\uD800-\uDBFF](?![\uDC00-\uDFFF])/;
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}
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// EXPORTS //
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module.exports = reUtf16UnpairedSurrogate;
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