blog.stevenlevithan.comA JavaScript and regular expression centric blog — Flagrant Badassery

Flagrant Badassery A JavaScript and regular expression centric blog Menu and widgets About Code Twitter: @ slevithan GitHub: slevithan Topics From My New Blog English teaching books Hyperphantasia Apps to learn Serbian CELTA lesson plans Dirty songs Karen Zerby Categories .NET (1) Books (10) Code Challenge (4) ColdFusion (4) Cross-Browser Issues (9) JavaScript (44) Performance (7) Project Releases (19) Regular Expressions (61) Unicode (3) VBScript (1) Yada Yada (14) More XRegExp: JavaScript regex library Awesome Regex: The best regex resources for all major regex flavors I created a curated list on GitHub of the best regular expression tools, tutorials, libraries, and many other resources . It covers all major regex flavors, and currently includes especially deep coverage of regular expressions in JavaScript (including a concise history of all regex features added to JavaScript in ES6 through ES2024, plus active proposals for the future). Check it out, and return to it easily with a handy shortcut URL: regex.cool . Posted on May 8, 2024 May 10, 2024 Categories Project Releases , Regular Expressions 1 Comment on Awesome Regex: The best regex resources for all major regex flavors parseUri 2.0: A mighty but tiny URI parser I created parseUri v1 17 years ago, but never hosted it on GitHub/npm because it’s older than both of those tools. Nevertheless, it’s been used very widely ever since due to it being tiny and predating JavaScript’s built-in URL constructor. After this short gap, I just released v2: github.com/slevithan/parseuri . It’s still tiny (nothing similar comes close, even with libraries that support far fewer URI parts, types, and edge cases), and it includes several advantages over URL : parseUri gives you many additional properties ( authority , userinfo , subdomain , domain , tld , resource , directory , filename , suffix ) that are not available from URL . URL throws e.g. if not given a protocol, and in many other cases of valid (but not supported) and invalid URIs. parseUri makes a best case effort even with partial or invalid URIs and is extremely good with edge cases. URL ’s rules don’t allow correctly handling many non-web protocols. For example, URL doesn’t throw on any of ’git://localhost:1234’ , ’ssh://myid@192.168.1.101’ , or ’t2ab:///path/entry’ , but it also doesn’t get their details correct since it treats everything after : up to ? or # as part of the pathname. parseUri includes a friendly” parsing mode (in addition to its default mode) that handles human-friendly URLs like ’example.com/index.html’ as expected. parseUri includes partial/extensible support for second-level domains like in ’//example.co.uk’ . Conversely, parseUri is single-purpose and doesn’t do normalization. But of course you can pass URIs through a normalizer separately, if you need that. Or, if you wanted to create an exceptionally lightweight URI normalizer, parseUri would be a great base to build on top of. ? So although it’s needed less often these days because of the built-in URL , if URL is ever not enough for your needs, this is an extremely accurate, flexible, and lightweight option. Check it out! parseUri on GitHub The demo page lets you easily test and compare results Changelog Tests Posted on April 5, 2024 May 10, 2024 Categories JavaScript , Project Releases Tags parseuri , uri Leave a comment on parseUri 2.0: A mighty but tiny URI parser Regex & Facebook Experience Tech Talk I recently gave a talk for a group of university students studying web development in Belgrade, Serbia. In it, I talked about my background, my experience starting in tech and eventually working at Facebook for seven years, and (most relevant to this blog) I spent about 20 minutes showing off some cool and advanced regular expressions. Specifically, regexes for switching Fahrenheit to Celsius, deleting repeated words, deleting non-adjacent duplicate lines, checking password complexity, reformatting names, adding thousands separators, matching balanced parentheses, and matching palindromes. You can find the video and slides here ( Lecture at SAE Belgrade: Lessons from Facebook ) or you can watch the video on YouTube (with the regex portion starting at 52:26). Posted on November 15, 2021 November 16, 2021 Categories Regular Expressions , Yada Yada Leave a comment on Regex & Facebook Experience Tech Talk New Blog ‘Lifecurious’ at slev.life Flagrant Badassery has been pretty quiet for years now, but it’s still my home for all things JavaScript and regular expression related. That said, I’ve just launched a shiny new blog where I’m posting about everything unrelated to programming. Want to learn about aphantasia and hyperphantasia , the time I unmasked cult leader Karen Zerby , why South Dakota residency is an ideal choice for nomads, or discover the best English teaching books ? All of these and more await at Lifecurious . Posted on February 26, 2021 June 14, 2022 Categories Yada Yada Leave a comment on New Blog ‘Lifecurious’ at slev.life XRegExp 3.0.0! After 3+ years, XRegExp 3.0.0 has been released. Standout features are dramatically better performance (many common operations are 2x to 50x faster) and support for full 21-bit Unicode (thanks to Mathias Bynens ). I’ve also just finished updating all the documentation on xregexp.com so go check that out. ? If you haven’t used XRegExp before, it’s an MIT licensed JavaScript library that provides augmented (and extensible!) regular expressions. You get new modern syntax and flags beyond what browsers support natively. XRegExp is also a regex utility belt with tools to make your client-side grepping and parsing easier, while freeing you from worrying about pesky cross-browser inconsistencies and things like manually manipulating lastIndex or slicing strings when tokenizing. Version 3.0.0 has lots of additional features, options, fine tuning, cross-browser fixes, some new simplified syntax, and thousands of new tests. And it still supports all the browsers. Check out the long list of changes . There are a few minor breaking changes that shouldn’t affect most people and have easy workarounds. I’ve listed them all below, but see the full changelog if you need more details about them. XRegExp.forEach no longer accepts or returns its context. Use binding with the provided callback instead. Moved character data for Unicode category L ( Letter ) from Unicode Base to Unicode Categories . This has no effect if you’re already using Unicode Categories or XRegExp-All . Using the same name for multiple named capturing groups in a single regex is now a SyntaxError . Removed the ’all’ shortcut used by XRegExp.install / uninstall . Removed the Prototypes addon, which added methods apply , call , forEach , globalize , xexec , and xtest to XRegExp.prototype . These were all just aliases of methods on the XRegExp object. A few changes affect custom addons only: changed the format for providing custom Unicode data, replaced XRegExp.addToken ’s trigger and customFlags options with new flag and optionalFlags options, and removed the this.hasFlag function previously available within token definition functions. You can download the new release on GitHub or install via npm . I’d love to hear feedback and common regex-related use cases that you think could be simplified via new XRegExp features. Let me know here or in GitHub issues. Thanks! Posted on September 24, 2015 September 26, 2015 Categories JavaScript , Project Releases , Regular Expressions Tags xregexp 2 Comments on XRegExp 3.0.0! Posts navigation Page 1 Page 2 … Page 18 Next page Proudly powered by...