Functional Programming & Haskell - Computerphile

Just what is functional programming? We asked a member of the team that created Haskell: John Hughes, Professor of Computer Science at Chalmers University of Technology in Gothenburg.

This video was filmed and edited by Sean Riley.

[DustinRodriguez_]

One of the things that the Haskell language should really get kudos for is its community. I've learned many different languages, and participated in many different communities around them, but the Haskell community is on a whole other level. I often felt bad about how far the people in the Haskell community would go to make sure I understood things. I would ask a question and I would always find someone willing to work with me for HOURS if necessary, writing all kinds of example code to show me things, walking me through difficult concepts, etc. Many languages have helpful communities, but the Haskell community is simply the best I've ever seen. Top notch folks all.

[FlashManinSpace]

My dad is an expert dragon slayer.
"eeer but I don't see any dragons around... "
You're welcome.

[barbariandude]

6:35 John Hughes goes full code ninja mode. God help any computer that tries to modify his data.

[CdeHwler]

Holy... that was very well explained. If you can get John back on camera that would be appreciated.

[Posiman]

Watching this in 2024, it's amazing to hear there was a time when there was no spam on facebook.

[simonalling]

After three years' CS studies at Chalmers, I always name Functional Programming (the very first course we took, and in which John played a major role) as the most valuable course — the one I would pick if I could choose only one single course to have taken.

Not only are functional languages absolutely fantastic to work with; one can also use many of the important concepts of FP in imperative languages like Java to write monumentally superior code.

[dynten]

How wonderful to see my first, and very best, programming professor again!

I took functional programming courses for prof Hughes in 2004. Very great memories from that time :-)

[ElagabalusRex]

I wish they had some concrete examples. A lot of these summaries of programming paradigms fail to show what problem solving looks like and how it differs from other paradigms.

[rootbeersoup]

Wow he must be an excellent teacher. You can tell he has a firm grasp on functional programming concepts because he can explain things in layman terms.

[Nathan]

I was a core Object Oriented programmer but over the past few months have shifted to using Clojure which is another Functional Language very similar to Haskell and OMG does Functional Programming make so much more sense than OOP!

Pure Functions means less bugs and the syntax of the language helps you write beautiful code that one can read so much more naturally. People who are getting into programming, give it a shot, you'll like it much more than OOP

[JeyPeyy]

He was my professor in parallel functional programming, he's fantastic! Koen Claessen who also teaches Haskell at Chalmers is also incredible and was the reason why I got interested in functional programming.

[rommelmartinez]

I had subtitles on, so naturally I was suprised when it mentioned the airline programming language.

[ioratv]

Having no side effects, now this is genius!
I was so impressed with functional programming that I spent last 5 years of my life coming up with an algorithm that can tell if a function is going to halt or not in O(1) time even.
I'd would like to share the code with you all but unfortunately that would be a side-effect so I can't.

[dealloc]

Few clarifications: Functional programming in at of itself doesn't mean you don't have side-effects. Functions that doesn't mutate and always provides the same output with the same input are called pure functions, which are part of the functional programming paradigm. Side effects are inevitable if you work with I/O such as networking, threads/multiple processes. You can still use functional programming languages (like Haskell) to write functions that handles side-effect, but it's usually done by separating them out from other business logic.


Scala is also not _really_ a functional programming language by itself. It is mix between functonal and object-oriented, similar to JavaScript.

[benoitranque]

I'm a javascript developer and I started programing funtionally and it makes so much sense I've never looked back

[lindhe]

This really made my day! I like Computerphile, I like Haskell and functional programming and I like John Hughes! He was such a great lecturer to have on my first course on university, and he left a good enough impression that three years after the course it still makes me excited to see him in a video!

[karlkastor]

He wrote QuickCheck? I used it during a Functional Programming course in uni. Very useful to make sure you got a function right fast.

[XetXetable]

I'd like to see a video on dependent types, and type systems in general, in the future. Types are extremely important to properly using languages like Haskell, and they have a rich history of interactions with the foundations of mathematics.

[bra]

I find this dude's enthousiasm very communicative. I would love to attend one of his classes. His students are lucky.

[doctorscoot]

I was taught Miranda in my first year of university, 1989. Twenty years later into my career spent mostly with C and Java and I was surprised to find it making comeback! (in the form of Haskell, Scala, etc).