I did my interpreter class in Scheme in university. The main thing it taught me was I never wanted to use scheme (or lisp) and put me off of functional programming for many years.
I re-did the interpreter from that class in C++ and it made insanely more sense to me than the scheme version. I could see where scheme was going and why it was a good fit but just hated it.
That same professor taught our C++ class (while learning it, they had someone quit) the next semester and they had to actually do a do-over he was so bad at C++. To his credit he knew as much half way through the semester (he had students getting ahead of him). He basically nop'd out of C++ like I did out of Scheme. It just didn't fit his brain.
Many people who like scheme and functional languages have an averse reaction to more procedural or OOP languages. It's interesting that people don't grok it can go the other way. But this is HN so I guess I'll explain.
A few things (and for context this was 1996).
With the class I disliked they were trying to teach me a language and a complex concept at the same time. In a 4 month semester, half of it was spent just getting basically proficient in the language. So instead of learning one concept I'm learning 2. We were essentially using scheme to build a interpreter for a simplified scheme. I understand why we were implementing scheme, it's one of the simplest languages to implement and maps well to many concepts in CS. this is actually why the game studio I worked at used it, not that it was the right language, in fact it's caused a lot of trouble and they have a lot of c/python like in the language now
Scheme seemed like a pretty useless language as well. The book for it listed (in the forward) out how amazing it was and showed all the amazing projects done with lisp-like languages. That list started with emacs and then the rest was academic things I'd never heard of, which seemed like a joke. If I recall scheme had some pretty weak language library functions at the time as well. Also at the time I cared about drawing triangles on the screen.
[I will lose points for this but it's my POV] I tend to find people who strongly like functional languages a bit insufferable, especially academics. I tend to learn by getting a real world project done, and I like tools that let you build real world things. I don't care anywhere near as much about form of the solution. . Functional languages seem to gel better with people who care about the beauty of a simple proof. I hate proofs. Also in much of the work I've done, the folks who really pushed for functional languages didn't really understand that most of their coworkers were juts not capable of understanding those languages or thinking that logically. There's a reason (imho) that they're not as popular of languages.
I have written stuff in these languages since then. I did work in the (gp reference) scripting language and on its implementation in the engine. This got me real features (like a mission in an AAA game, and features for my mission designers in the engine). This seemed useful to me.
I spent about 3 months trying to use Clojure to do a highly parallel data processing work. It seemed to map well to the problem. However it was insufferably slow, and with required type hinting was essentially complicated java (lost the benefit). I re-wrote it in C++ in about a week and brought the processing time from 15 minutes to 32 seconds by leveraging the deeper parts of the machine (buffers, disk cache, physical cores) which were not as available inside the abstraction.
So it also comes down to I haven't found a problem that maps well to something like scheme that I need to solve. When I do stuff with interpreters I just grab ANTLR and java/go/c++. This is more maintainable for everyone I work with.
I think some points are unfair. I have physical anger when I use java prior 8, but I do appreciate smalltalk a lot more, it tickles my sense of curiosity, joy.
While I do admit that lisp/scheme/fp seek beauty.. it's also one thing I want in coding. Beautiful code. Not at the expense of practicality.. but still, look at how easy it is to be confused and make a mess trying to write a flatmap like procedure, while in lisp it's so trivial you never even think about it.
Thanks for the honesty and good job on making things fast.
I think your view’s totally reasonable. In my experience, the benefit of FP is To teach good program design: I’ve observed that functional programming languages encourage good practices that can be practiced in any language. For example: pushing I/O to the leaves of your program, dependency injection, eradicating global state, focus on functional interfaces.
These are patterns that you can do in any language, but functional languages kind of compel you to follow them. Many people first learned these patterns from FP, and carry them over to OOP, which they have to write at work.
I don’t know if there are many problems that are elegantly defined for FP, as you suggest. I think people just get comfortable in their cages. :)
You’re not alone. My brain works in steps, not proofs. If all code looked like Haskell and friends I doubt I’d ever have gotten into it in the first place.
[edit] algos, over proofs, would probably be a better way to put it.
I did my interpreter/PLT class in OCaml and absolutely loved it. I yearn for things like ADTs and pattern matching in other languages I use now :'(
Another benefit (I guess the primary benefit) was that my interpreter programs written in OCaml ended up looking nearly identical to my proofs/definitions. Doing it imperatively would add a nasty layer of indirection.
If you already knew C++, that's not a particularly useful comparison. Of course you were more comfortable reading and writing code in a language you already knew, than one you were learning.
An equivalent would be a class teaching c++ and writing and interpreter at the same time. And my gut says that would be more complex for unnecessary reasons than the class you took.
I did not already know C++. I did already know Java since we did java for our intro class (101/102) and then the next year we did Compiler theory (240). But the professors who know more than me an entry level student designed this structure.
And I did write that same compiler in c++ and sure it was more lines of code but I understood it better.
I've also worked on a scheme interpreter in C++ that someone wrote in a game engine and it wasn't all that complicated.
There are plenty of programmers who learned languages like Haskell, Scheme, Eiffel etc. as their first languages who are now programming in Java, JavaScript, C# etc.
There are just way more courses/universities that teach or taught Java/Python.
Businesses settle on the lowest common denominator it seems.
I re-did the interpreter from that class in C++ and it made insanely more sense to me than the scheme version. I could see where scheme was going and why it was a good fit but just hated it.
That same professor taught our C++ class (while learning it, they had someone quit) the next semester and they had to actually do a do-over he was so bad at C++. To his credit he knew as much half way through the semester (he had students getting ahead of him). He basically nop'd out of C++ like I did out of Scheme. It just didn't fit his brain.