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diff --git a/_articles/2020-11-08-the-next-paradigm-shift-in-programming-video-review.md b/_articles/2020-11-08-the-next-paradigm-shift-in-programming-video-review.md deleted file mode 100644 index c98c131..0000000 --- a/_articles/2020-11-08-the-next-paradigm-shift-in-programming-video-review.md +++ /dev/null @@ -1,164 +0,0 @@ ---- - -title: The Next Paradigm Shift in Programming - video review - -date: 2020-11-08 - -layout: post - -lang: en - -ref: the-next-paradigm-shift-in-programming-video-review - -eu_categories: video review - ---- - -This is a review with comments of -"[The Next Paradigm Shift in Programming][video-link]", by Richard Feldman. - -This video was *strongly* suggested to me by a colleague. I wanted to discuss it -with her, and when drafting my response I figured I could publish it publicly -instead. - -Before anything else, let me just be clear: I really like the talk, and I think -Richard is a great public speaker. I've watched several of his talks over the -years, and I feel I've followed his career at a distance, with much respect. -This isn't a piece criticizing him personally, and I agree with almost -everything he said. These are just some comments but also nitpicks on a few -topics I think he missed, or that I view differently. - -[video-link]: https://www.youtube.com/watch?v=6YbK8o9rZfI - -## Structured programming - -The historical overview at the beginning is very good. In fact, the very video I -watched previously was about structured programming! - -Kevlin Henney on -"[The Forgotten Art of Structured Programming][structured-programming]" does a -deep-dive on the topic of structured programming, and how on his view it is -still hidden in our code, when we do a `continue` or a `break` in some ways. -Even though it is less common to see an explicit `goto` in code these days, many -of the original arguments of Dijkstra against explicit `goto`s is applicable to -other constructs, too. - -This is a very mature view, and I like how he goes beyond the -"don't use `goto`s" heuristic and proposes and a much more nuanced understanding -of what "structured programming" means. - -In a few minutes, Richard is able to condense most of the significant bits of -Kevlin's talk in a didactical way. Good job. - -[structured-programming]: https://www.youtube.com/watch?v=SFv8Wm2HdNM - -## OOP like a distributed system - -Richard extrapolates Alan Kay's original vision of OOP, and he concludes that -it is more like a distributed system that how people think about OOP these days. -But he then states that this is a rather bad idea, and we shouldn't pursue it, -given that distributed systems are known to be hard. - -However, his extrapolation isn't really impossible, bad or an absurd. In fact, -it has been followed through by Erlang. Joe Armstrong used to say that -"[Erlang might the only OOP language][erlang-oop]", since it actually adopted -this paradigm. - -But Erlang is a functional language. So this "OOP as a distributed system" view -is more about designing systems in the large than programs in the small. - -There is a switch of levels in this comparison I'm making, as can be done with -any language or paradigm: you can have a functional-like system that is built -with an OOP language (like a compiler, that given the same input will produce -the same output), or an OOP-like system that is built with a functional language -(Rich Hickey calls it -"[OOP in the large][langsys]"[^the-language-of-the-system]). - -So this jump from in-process paradigm to distributed paradigm is rather a big -one, and I don't think you he can argue that OOP has anything to say about -software distribution across nodes. You can still have Erlang actors that run -independently and send messages to each other without a network between them. -Any OTP application deployed on a single node effectively works like that. - -I think he went a bit too far with this extrapolation. Even though I agree it is -a logical a fair one, it isn't evidently bad as he painted. I would be fine -working with a single-node OTP application and seeing someone call it "a *real* -OOP program". - -[erlang-oop]: https://www.infoq.com/interviews/johnson-armstrong-oop/ -[langsys]: https://www.youtube.com/watch?v=ROor6_NGIWU -[^the-language-of-the-system]: From 24:05 to 27:45. - -## First class immutability - -I agree with his view of languages moving towards the functional paradigm. -But I think you can narrow down the "first-class immutability" feature he points -out as present on modern functional programming languages to "first-class -immutable data structures". - -I wouldn't categorize a language as "supporting functional programming style" -without a library for functional data structures it. By discipline you can avoid -side-effects, write pure functions as much as possible, and pass functions as -arguments around is almost every language these days, but if when changing an -element of a vector mutates things in-place, that is still not functional -programming. - -To avoid that, you end-up needing to make clones of objects to pass to a -function, using freezes or other workarounds. All those cases are when the -underlying mix of OOP and functional programming fail. - -There are some languages with third-party libraries that provide functional data -structures, like [immer][immer] for C++, or [ImmutableJS][immutablejs] for -JavaScript. - -But functional programming is more easily achievable in languages that have them -built-in, like Erlang, Elm and Clojure. - -[immer]: https://sinusoid.es/immer/ -[immutablejs]: https://immutable-js.github.io/immutable-js/ - -## Managed side-effects - -His proposal of adopting managed side-effects as a first-class language concept -is really intriguing. - -This is something you can achieve with a library, like [Redux][redux] for JavaScript or -[re-frame][re-frame] for Clojure. - -I haven't worked with a language with managed side-effects at scale, and I don't -feel this is a problem with Clojure or Erlang. But is this me finding a flaw in -his argument or not acknowledging a benefit unknown to me? This is a provocative -question I ask myself. - -Also all FP languages with managed side-effects I know are statically-typed, and -all dynamically-typed FP languages I know don't have managed side-effects baked in. - -[redux]: https://redux.js.org/ -[re-frame]: https://github.com/Day8/re-frame - -## What about declarative programming? - -In "[Out of the Tar Pit][tar-pit]", B. Moseley and P. Marks go beyond his view -of functional programming as the basis, and name a possible "functional -relational programming" as an even better solution. They explicitly call out -some flaws in most of the modern functional programming languages, and instead -pick declarative programming as an even better starting paradigm. - -If the next paradigm shift is towards functional programming, will the following -shift be towards declarative programming? - -[tar-pit]: http://curtclifton.net/papers/MoseleyMarks06a.pdf - -## Conclusion - -Beyond all Richard said, I also hear often bring up functional programming when -talking about utilizing all cores of a computer, and how FP can help with that. - -Rich Hickey makes a great case for single-process FP on his famous talk -"[Simple Made Easy][simple-made-easy]". - -[simple-made-easy]: https://www.infoq.com/presentations/Simple-Made-Easy/ - -<!-- I find this conclusion too short, and it doesn't revisits the main points --> -<!-- presented on the body of the article. I won't rewrite it now, but it would be an --> -<!-- improvement to extend it to do so. --> |