It's a port from the wonderful python project https://github.com/vi3k6i5/flashtext, for internals of the algorithm look there.
This algorithm allows you to extract or replace several keywords at ones. If you deal with 300 keywords, which have 5 variants each a regex approach is slower than the flashtext approach. For 1000 keyword with 5 variants each the regex can't be build.
In PHP 5.6 using regex is really slow. In newer verions it performs better.
composer require shdev/phpflashtext
<?php
use Shdev\FlashText\KeywordProcessor;
$keywordProcessor= new KeywordProcessor();
$keywords = [
'java' => ['java_2e', 'java programing'],
'product management' => ['product management techniques', 'product management'],
];
$keywordProcessor->addKeywordsFromAssocArray($keywords);
$sentence = 'I know java_2e and product management techniques';
$keywordsExtracted = $keywordProcessor->extractKeywords($sentence);
// $keywordsExtracted = ['java', 'product management']
$keywordsExtractedWithSpanInfo = $keywordProcessor->extractKeywords($sentence, true);
// $keywordsExtractedWithSpanInfo = [
// ['java', 7, 14],
// ['product management', 19, 48],
//]
$sentenceNew = $keywordProcessor->replaceKeywords($sentence);
// $sentenceNew = 'I know java and product management';
The original paper published on FlashText algorithm.
@ARTICLE{2017arXiv171100046S,
author = {{Singh}, V.},
title = "{Replace or Retrieve Keywords In Documents at Scale}",
journal = {ArXiv e-prints},
archivePrefix = "arXiv",
eprint = {1711.00046},
primaryClass = "cs.DS",
keywords = {Computer Science - Data Structures and Algorithms},
year = 2017,
month = oct,
adsurl = {http://adsabs.harvard.edu/abs/2017arXiv171100046S},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
The article published on Medium freeCodeCamp.