Why Isn't Functional Programming the Norm? – Richard Feldman

This is indeed a very interesting question! I’ve also asked myself that time and time again, along the path of slowly discovering what this FP thing is all about over the course of my career. It does look wonderful, it does save you a lot of effort in some cases, where “some” is a vast swathes of computational problems. And its so damn elegant. A lot of examples are thrown around were a bunch of lambda calculus can result in 10-20 fold reduction in source code size. So where’s the catch?There has to be something wrong right? Well recently I stumbled upon a clojure conf talk that tried to tackle precisely this question. [VIDEO] The short of it is that its more of a historical inertia and chance than any specific hidden gotcha. Fascinating talk.

This talk by Richard Feldman is an excellent discussion about why Functional Programming is not the norm - [VIDEO]

I know the answer, thanks to watching a recent video by Richard Feldman on why functional programming isn’t popular yet. I recommend watching it for some interesting talk about programming languages in general, it’s on YouTube at [VIDEO] Anyway what privates give you is what everyone wants from a programming language: modularity. We want to be able to expose an api to some code and for it to have some inner workings that we don’t see because: 1. If we know they can’t be touched we have some implicit guarantees about our program. E.g. the mouse pointer cannot go off screen even if we try to make a call to do that. 2. It is simpler for a programmer to understand the api which might be 1% of the size of the module itself with all private’s. 3. I can change my private’s without breaking your calls. Essentially a minor version change in Semvar parlance instead of a major breaking change. 4. Make impossible state impossible! By guarding the state. All these things require modularity, and OO uses classes and private members to provide that modularity. Elm uses modules and the exposing keyword (or lack of!) as a contrast. JS modules are similar with a lack of an export allowing you to hide something. That something you did export can use for state or functionality. There is an old IIFE trick that works this way also. Making everything public is a bad idea, as you miss out on modularity advantages. Not sure how Ruby hides things as I haven’t used it for a while but I’m sure there is a

In the market of ideas, there usually isn't any reason that makes the good ideas unpopular. That's the default outcome. Some good ideas eventually make it to mainstream / conventional wisdom because there's some second factor that brings them to the spotlight. For languages it might be a killer app, big corporate investment, etc. In [VIDEO] Richard Feldman puts up a (well founded IMO) argument that OO became accidentally popular because of C++. C++ didn't do OO well, nor was OO the main benefit of C++, it just happened to be something that came with C++.

“Why isn’t functional programming the norm?” by Richard Feldman. Spoiler: not on the basis of merits. [VIDEO] “React to the future” by Jordan Walke. Why ReasonML is a logical extension of ReactJS’ programming paradigm. [LINK] “Typing the untyped: soundness in gradual type systems” by Ben Weissmann. The trade offs that various gradual type systems make based on their language constraints. [LINK] “Let’s program like it’s 1999” by Lee Byron. How the mutual feedback loop of abstraction, syntax and mental model drives the evolution of web technologies. [LINK]

> If in the next fifty years more than, say, 3% of programmers will be programming in a language like Lean, I will eat my hat. You're not even putting any stakes on the table. That's such a safe bet. It's unlikely you'd even have a chance at losing the odds are so stacked. There's a great talk on why functional programming is not the norm: [VIDEO] The short of it is: network effects . Haskell, OCaml, SML... they've never had the benefit of being the exclusive language to a popular platform like the web, macOS, or UNIX. They've not yet had a killer app like Rails or Numpy/SciPy/PyTorch. They've certainly not been foisted on the market with a war chest of marketing dollars like Java and C#. And they're not an incremental improvement on the status quo with an obvious, easy benefit. > Now, try to explain to a programmer what kind of object id is That's a rhetorical exercise. You can take a random snippet of APL or Fortran and the outcome would be the same. Every language requires training and effort to learn. I teach people Haskell and TLA+. If you think teaching people the value of a language like Haskell is hard you should see the blank stares I get on the first day teaching experienced developers TLA+. Interested folks will come around eventually and have their moment but it takes training and dedication to get there. > was chosen not with the best interests of programmers in mind I'm well aware. I converse regularly with the maintainers of mathlib and the community. I know th

Richard Feldman gave an interesting talk on this in 2019 [0]. He was trying to answer why functional programming isn't mainstream but the opposite is what we're posing here and I think it's for many of the same reasons. Network effects : a lot of these languages were mainstream earlier on and got buy in from a lot of folks who are invested in their continued adoption and success. Platform exclusivity : some companies push their own language ecosystems on their platforms and those languages are often OOP/multi-paradigm languages. Specifically to OOP we have to ask why is the particular style of C++/Java OOP the norm? Why didn't Eiffel, Smalltalk, or Self reach the same market? [0] [VIDEO] edit : forgot the link -- oops.

Keep in mind that what may seem like "personality fit" may be more related to "learned imperative programming first". As an analogy, depending on which spoken language a person learned first (as a child, _automatically), learning some new languages may be particularly difficult or quite natural. If we had all learned functional programming concepts first, our minds would be trained to think that way. We all learned functional (declarative) math, and we don't even think about it as such. It's just math. This video gives some plausible explanations as to why imperative programming is more common than functional: [VIDEO]