111 lines
3.3 KiB
JavaScript
111 lines
3.3 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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// MODULES //
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var isString = require( '@stdlib/assert/is-string' ).isPrimitive;
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var splitGraphemeClusters = require( './../../split-grapheme-clusters' );
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var isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' ).isPrimitive;
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var isStringArray = require( '@stdlib/assert/is-string-array' ).primitives;
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var replace = require( './../../replace' );
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var rescape = require( '@stdlib/utils/escape-regexp-string' );
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var format = require( './../../format' );
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// VARIABLES //
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var WHITESPACE_CHARS = '\u0020\f\n\r\t\v\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff';
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// MAIN //
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/**
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* Trims `n` characters from the end of a string.
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*
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* @param {string} str - input string
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* @param {NonNegativeInteger} n - number of characters to trim
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* @param {(string|StringArray)} [chars] - characters to trim (defaults to whitespace characters)
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* @throws {TypeError} first argument must be a string
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* @throws {TypeError} second argument must be a nonnegative integer
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* @throws {TypeError} third argument must be a string or an array of strings
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* @returns {string} trimmed string
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*
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* @example
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* var str = ' abc ';
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* var out = rtrimN( str, 2 );
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* // returns ' abc '
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*
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* @example
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* var str = ' abc ';
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* var out = rtrimN( str, str.length );
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* // returns ' abc'
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*
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* @example
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* var str = '~~abc!~~';
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* var out = rtrimN( str, str.length, [ '~', '!' ] );
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* // returns '~~abc'
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*
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* @example
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* var str = '🤖👨🏼🎨🤖👨🏼🎨🤖👨🏼🎨';
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* var out = rtrimN( str, str.length, '👨🏼🎨🤖' );
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* // returns ''
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*/
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function rtrimN( str, n, chars ) {
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var nElems;
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var reStr;
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var isStr;
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var RE;
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var i;
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if ( !isString( str ) ) {
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throw new TypeError( format( 'invalid argument. Must provide a string. Value: `%s`.', str ) );
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}
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if ( !isNonNegativeInteger( n ) ) {
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throw new TypeError( format( 'invalid argument. Must provide a nonnegative integer. Value: `%s`.', n ) );
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}
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if ( arguments.length > 2 ) {
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isStr = isString( chars );
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if ( !isStr && !isStringArray( chars ) ) {
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throw new TypeError( format( 'invalid argument. Must provide a string or an array of strings. Value: `%s`.', chars ) );
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}
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if ( isStr ) {
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chars = splitGraphemeClusters( chars );
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}
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nElems = chars.length - 1;
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reStr = '';
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for ( i = 0; i < nElems; i++ ) {
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reStr += rescape( chars[ i ] );
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reStr += '|';
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}
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reStr += rescape( chars[ nElems ] );
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// Case: Trim a specific set of characters from the end of a string..
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RE = new RegExp( '(?:' + reStr + '){0,'+n+'}$' );
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} else {
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// Case: Trim `n` whitespace characters from the end of a string...
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RE = new RegExp( '[' + WHITESPACE_CHARS + ']{0,'+n+'}$' );
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}
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return replace( str, RE, '' );
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}
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// EXPORTS //
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module.exports = rtrimN;
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