time-to-botec

Benchmark sampling in different programming languages
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main.js (3031B)

      1 /**
      2 * @license Apache-2.0
      3 *
      4 * Copyright (c) 2021 The Stdlib Authors.
      5 *
      6 * Licensed under the Apache License, Version 2.0 (the "License");
      7 * you may not use this file except in compliance with the License.
      8 * You may obtain a copy of the License at
      9 *
     10 *    http://www.apache.org/licenses/LICENSE-2.0
     11 *
     12 * Unless required by applicable law or agreed to in writing, software
     13 * distributed under the License is distributed on an "AS IS" BASIS,
     14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15 * See the License for the specific language governing permissions and
     16 * limitations under the License.
     17 */
     18 
     19 'use strict';
     20 
     21 // MODULES //
     22 
     23 var isString = require( '@stdlib/assert/is-string' ).isPrimitive;
     24 var isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' ).isPrimitive;
     25 var numGraphemeClusters = require( './../../num-grapheme-clusters' );
     26 var nextGraphemeClusterBreak = require( './../../next-grapheme-cluster-break' );
     27 var format = require( './../../format' );
     28 
     29 
     30 // MAIN //
     31 
     32 /**
     33 * Truncates a string to a specified length.
     34 *
     35 * @param {string} str - input string
     36 * @param {integer} len - output string length (including ending)
     37 * @param {string} [ending='...'] - custom ending
     38 * @throws {TypeError} first argument must be a string
     39 * @throws {TypeError} second argument must be a nonnegative integer
     40 * @throws {TypeError} third argument must be a string
     41 * @returns {string} truncated string
     42 *
     43 * @example
     44 * var str = 'beep boop';
     45 * var out = truncate( str, 7 );
     46 * // returns 'beep...'
     47 *
     48 * @example
     49 * var str = 'beep boop';
     50 * var out = truncate( str, 5, '>>>' );
     51 * // returns 'be>>>'
     52 *
     53 * @example
     54 * var str = 'beep boop';
     55 * var out = truncate( str, 10 );
     56 * // returns 'beep boop'
     57 *
     58 * @example
     59 * var str = 'beep boop';
     60 * var out = truncate( str, 0 );
     61 * // returns ''
     62 *
     63 * @example
     64 * var str = 'beep boop';
     65 * var out = truncate( str, 2 );
     66 * // returns '..'
     67 *
     68 * @example
     69 * var str = '🐺 Wolf Brothers 🐺';
     70 * var out = truncate( str, 6 );
     71 * // returns '🐺 W...'
     72 */
     73 function truncate( str, len, ending ) {
     74 	var endingLength;
     75 	var fromIndex;
     76 	var nVisual;
     77 	var idx;
     78 	if ( !isString( str ) ) {
     79 		throw new TypeError( format( 'invalid argument. First argument must be a string. Value: `%s`.', str ) );
     80 	}
     81 	if ( !isNonNegativeInteger( len ) ) {
     82 		throw new TypeError( format( 'invalid argument. Second argument must be a nonnegative integer. Value: `%s`.', len ) );
     83 	}
     84 	if ( arguments.length > 2 ) {
     85 		if ( !isString( ending ) ) {
     86 			throw new TypeError( format( 'invalid argument. Third argument must be a string. Value: `%s`.', ending ) );
     87 		}
     88 	}
     89 	ending = ending || '...';
     90 	endingLength = numGraphemeClusters( ending );
     91 	fromIndex = 0;
     92 	if ( len > numGraphemeClusters( str ) ) {
     93 		return str;
     94 	}
     95 	if ( len - endingLength < 0 ) {
     96 		return ending.slice( 0, len );
     97 	}
     98 	nVisual = 0;
     99 	while ( nVisual < len - endingLength ) {
    100 		idx = nextGraphemeClusterBreak( str, fromIndex );
    101 		fromIndex = idx;
    102 		nVisual += 1;
    103 	}
    104 	return str.substring( 0, idx ) + ending;
    105 }
    106 
    107 
    108 // EXPORTS //
    109 
    110 module.exports = truncate;