Regular expressions as finite automata

[@supermage8026]

I just wanted to express how lucky we are to have someone like you doing this! It's rare to find such good explanations of computer science and mathematical concepts these days.

[@aescling]

years ago Russ Cox wrote a series of blog posts on regular expressions that this video series is obviously following closely, in particular the first post in the series, “Regular Expression Matching Can Be Simple and Fast”

[@tau9632]

Wow what an incredible educational resource! Thank you so much!

[@Pablo360able]

Great video! Now I feel like I finally understand that it's "clay knee".

[@justinbrady2900]

This took a whole semester to grok back in 2000. Concise explanation.

[@VictorMantovani]

tks youtube algorithm for recommending this amazing channel

[@esra_erimez]

5:40 what follows is one of the most brillant insights and explanations in computer science. You are most impressive.

[@maxmustermann5590]

Man I just dived into the rabbit whole of büchli automata a couple of days ago and then you drop this masterpiece. Thank you!!

[@mehrdadkhorasani6009]

This channel is truly one of the best of our time, deserving of recognition and appreciation.

[@randomsearches369]

We love you, Kay!

[@LESAORAS]

this was a great refresher for the like 5 courses about languages and automatons and their uses i've attended while doing my compsci masters. good video

[@chriskindler10]

this channel has by far become my favourite with regards to programming :)

[@rafaelfreire3792]

What a pleasant surprise! Thank you so much for these videos

[@Dan-km8zy]

Love your presentation and video editing style. Thanks for everything

[@Paul_ABC]

Content quality is amazing. You're spoiling us

[@jimwiley9275]

Really enjoyed this one... Please never stop making these!

[@404willum]

Less than 3 minutes in and this is already a banger, thanks for the hard work !

[@davidebiondani3062]

Maybe the best channel on KZbin, amazing

[@esra_erimez]

Agreed!

[@Vukleidon]

Had me worried that you gave up on the project. Honestly I have to say over the past few weeks, this channel has become one of my favorites. I really hope you will keep on doing the great work!!!

[@moormoor4281]

Im listening

[@vk8a8]

ok thanks for letting us know

[@rudranathmistry6957]

😂

[@moormoor4281]

Thanking you most kindly from English England

[@connorkapooh2002]

What gets you excited, Moor Moor?

[@esra_erimez]

Fun fact: Regular expressions were invented by Stephen Kleene. They were later popularized by Ken Thompson when he wrote the "ed" editor for Unix. Edit: I wrote this before I saw you had it in your video, once again you continue to impress.

[@3ombieautopilot]

Thank you for making these. Such a rare gem.

[@ElaineParra]

Hey Kay I am happy we have you as reference and mentor in this journey learning programming and diving in such fundamentals in CS. What in couple of months was really challenging with discipline, effort, motivation and love for the things you like to do at the end we overcome any obstacle! Love for the 0de5

[@barcellos-pedro]

Wow, you are amazing! Thanks for making this video!

[@jaketrzcinski8141]

Another banger, Queen! Thanks for putting this together so eloquently!

[@amichelis]

This video encapsulates so well part of what I'm trying to make right now... I'm in awe! Can't wait for the next one! (context: I'm in the process of creating a lexer-parser duo, tailored for educational purposes. It'll take the user through a step-by-step visual journey of how lexing and parsing work, enabling educators to better explain the inner workings of a compiler... Still in very early stages, only parsing is implemented currently... Wish me luck :') )

[@ComputerBread]

Sounds amazing, good luck :)

[@user-cg8ez7dz9l]

Your videos are actually excellent! This has made me a big fan

[@GabrielAnguitaVeas]

Hola! Infinitamente agradecido, eres una artista

[@BigLongRandomNumberNameM-kf9vy]

I wrote a grammar as a deterministic finite state machine in C. Each state is a function which takes a character and returns a pointer to the next function. On the one hand, I love the simplicity of not needing special data types. I love that, if you wanted to "wrap" it, you just write functions that call functions and return functions. I love that you can test each state is correct in isolation. But I hated that it turned my programming task into a data entry task 😅

[@Shdnfncidjen]

Cheers and thanks for sharing! Loving your videos!

[@supercompooper]

I remember this in my first year university courses. We had to write code that would convert the NDFA to a DFA 😊 takes me back

[@Googleguy-1]

new video yay, your videos are amazing!!!

[@y9tw0t]

Another banger. Love your way of going through shit! Already eagerly anticipating your next vid -whatever it may be about.

[@Caracuan12]

Excellent video, thanks for the detailed explanation.

[@ethanweller3013]

This series is wonderful. It would be nice to have the playlist for it start with the intro and go down from there, would be much easier to watch that way.

[@justinbrady2900]

These are the data structures we use for fast pattern matching on firewalls when scanning for malware and intrustions too, with some optimizations. At some point of growing the memory backing them got to hundreds of MB, scouts honor. We got yelled at.

[@lterego]

A lot and very good content in such a short clip. Just a nitpick: at 19:46 "any_char" creeps in instead of "single_char"... some tests work just because the string length are the same as for correct strings (and what should be incorrect strings).

[@offYears]

thanks for pointing this out, i was confused as to why any_char was accepting an argument there

[@br3nto]

Great video! I wish they had taught automata like this at uni

[@flippert0]

Wasn't aware about the "Clean" vs "Clay-Knee" controversy. Seemingly (or according to his son Ken Kleene), Stephen C. Kleene invented this peculiar pronunciation of his name all by his own. One remark about 'automata', though. It's a plural for 'automaton'. So it's 'several automata' but 'one automaton'.

[@cruzg3dev]

Oh my!!! This is so gooood! Thanks!!!

[@joe_hoeller_chicago]

What a great video-thank you!!!❤

[@Sami_K99]

Heyyy, long time no see, thanks for the vid ✨

[@klirmio21]

Noam Chomsky, a linguist and still got influence in Computer Science world. Insane!

[@emir5146]

Omg so thanks because that is what i need.

[@programmer1356]

As usual, great stuff. Klaynee always gets me too - waaaay back we only had books and had to make up pronunciation (Runge ouch).

[@alphmega]

This was worth a like for the Dijkstra reference alone.

[@isaacalves6846]

Hey, I'm studying finite automata in college right now!

[@TWinKIeAssasN]

I took compilers and automata theory last semester and it was hell 😭 that class took over my life for that whole semester

[@bt64u30]

+1

[@fudencio]

amazing video.

[@JinKee]

I remember learning lex and yacc back in my compiler design course. I was so proud of barely scraping by on a pass, the only person who got a HD did it by failing three subjects and his girlfriend left him.

[@thebirdhasbeencharged]

The videos are getting cleaner and cleaner

[@deryilz]

great video!

[@br3nto]

Totally pronounced RegEx, Reg as is in Reginald because it rolls off the tongue better! Or even ReJex. It’s got good mouth feel and ear feel.

[@Zaniahiononzenbei]

I thoroughly hope you dig into the irregular expressions. :( they make me sad. They are nice features to have on occasion, but I think its beauty is someahat like C's beauty. By pushing some useful features out of scope we end up with a tool that is more obviously the right or wrong tool at a given time. C did this with the preprocessor, calling conventions, dynamic dependencies, and symantics for threading. They're all externally defined, and they're all hard problems that need to be solved. There's a lot in regex libraries that feels like its a cool tool, but it feels weird that its there.

[@DeepVoiceSatish]

Thanks for providing

[@LeonMerk123]

Amazing video

[@AlberTesla1024]

What a coincidence, i learnt FSM and state pattern. Thanks btw.

[@martinsanchez-hw4fi]

It would be nice to have a video on the lexic analysiss a compiler does

[@alexibnz]

to quote people on other social networks: am I on KZbin Premium? Absolutely amazing video

[@iamblue8272]

This remember me a code wars challenge : "Regular Expression - Check if divisible by 0b111 (7)" where i had to convert a DFA into a regex. Spent hour trying on paper and never finished this kata

[@WhizPill]

Interesting channel

[@volbla]

9:03 This needs a plus after the parenthesis. As it is it will only match exactly two "a"s.

[@Brice23]

Takes me back to 2018, my first semester in computer science..

[@yan-amar]

2:08 I didn't know automata were invented and useful outside of computer science. I looked it up and it seems quite interesting.

[@BooVoidCat]

21:54 Question: Is there a reason why this is not done by just merging the final state of the left graph with the initial state of the right graph? It seems to me that any state which has only one transition and said transition is an epsilon transition could simply be merged with the succeeding state. Is this correct, or is there a case that I'm missing where that extra transition is necessary or useful?

[@MalikMehsi]

Wish i would've had videos like these when i took my theoretical computer science class... Shit was brutal

[@SnuffPuppyLexy]

Thank you so much

[@raelwert2344]

Love your channel! Let me know if you are still looking for a copy of regular expressions and state graphs!

[@joel.9543]

Nice video! I have some technical questions: What do you use to make animations? What video editor do you use?

[@zadymew7885]

One question. How does the construction deal with us applying the kleene star twice to the NFA?. I found myself implementing this on Haskell and when i tried to plug a parser into it, the string "(a*)*" fried my pc

[@marouaniAymen]

Thanks for the excellent video, but one think I did not understand is how to go from a literal regular expression (I mean the string text itself for example (a*b+)+) I create the automata, seems that we have circular problem here because we need to parse the text itself, which means an automaton, any idea please ? perhaps this can be the subject of a future video, thanks.

[@zadymew7885]

They already uploaded a video dedicated to parsing!

[@dr.mounir.mallek]

I do have the paper by McNaughon and Yamada in case you still need it.

[@Justhere369]

Hey Kay, nice video , please what is the name of the software you are using ? ..... Is it JFlap

[@bananaear23]

Ur back wohooo

[@bananaear23]

also how do I like twice

[@SimGunther]

Simply put, regex needs to be transformed into an NFA before that turns into a DFA that can simplified and transformed into a table driven automaton for those nice tight loops in code 😊

[@JayDee-b5u]

I think I have an implementation that doesn't require shunting yard nor dfa/nfa. A simple pratt parser and binary (and unary) tree is all that is needed. :)

[@flippert0]

Of course many people know how to use regexes (every programmer _must_ know them), but few peope actually can build a regex engine. I knew about DFAs and NFAs but your lecture enables me to actually build one of my own (for fun and giggles). Thanks!

[@unbearablepun8608]

This would’ve been so helpful a semester ago 😭

[@imlemonth]

This makes me wanna do it myself in python 😅

[@demerzel3333]

great content, this has way less views than it deserves

[@zweitekonto9654]

the code highlighting lacks a bit of contrast which makes it difficult to read.

[@mo938]

You’re so smart! Makes me feel dumb lol

[@jarno4054]

Half of my semester in 30 minutes 🙏

[@josephlagrange9531]

Hi, Kay!

[@ДаниилИмани]

Please, rearrange the ODE5 megalist in chronological order

[@neoeno4242]

Have now done - apologies, I thought that was a viewer-setting but I now realise it is mine!

[@ForsakenDAemon]

Not sure whether you’ve managed to get hold of it otherwise, but just flicked you a copy of McNaughton and Yamada (1960) for educational purposes!

[@brulsmurf]

@6:00 I felt nothing but the void within.

[@ngideo]

Languages! Now we're cookin'!

[@eterr9000]

I recently learned about LISP Scheme and I am noticing something that looks like Scheme expression 👀

[@Satyam1010-N]

Happy deepawali light a candle lamps (100+)at main house , may the light remove all kind of darknes self doubt bad habits bad thoughts , your life lights up , happy deepawali Kay

[@ahmedAltariqi]

What tool you used to make the slides?

[@kevinbatdorf]

Where is chapter 1?

[@peterbann4759]

I think they are included in Python (I'm learning Python)

[@eduardrieraraurell3328]

the regular expression for even number of a's should be (h*ah*ah*)* isn't it?

[@zenkira_]

holy graph

[@whtiequillBj]

your 0DE5 playlist is backwards

[@VioletJewel1729]

girllll it's re jex >:((((( ~

[@Truth-p7c]

Wow

[@Johnmoe_]

I see regex I click 😊

[@starlonga]

I pronounced it as «Clean» (Klenee)

[@chrisleon27]

Cellular automata

[@ponirvea]

great video! i think you forgot a cut around 15:32