[physicles]

This is a tour de force, and it accomplishes the goal of enabling FP using the Go syntax and toolchain.

But code written using this library is no longer Go: most Go programmers can't grok it, and it's awkward to call normal Go libraries because there's no way to know if that function you're calling is pure.

If your goal is to "make it easy and fun to write maintainable and testable code in golang" by making pure functions first-class, is there another way to do that without inventing a new language?

From experience and inspired by Carmack's classic essay on FP in C++[1], I tend toward a functional style: minimize state, treat locals as const, avoid non-const globals, enable parallelism by isolating state. Go makes it easy to write static analysis tools, so go vet could be augmented to, for example, keep track of which functions are pure, and show some yellow underlines at those places where input parameters are mutated.

I'd use something like that.

[1] http://sevangelatos.com/john-carmack-on/

[Cthulhu_]

It's syntactically Go but it adds a functional DSL on top of it - that is, you can't just know Go, you need to learn the ins and outs of this library too (plus functional programming) before you can use it.

I cannot recommend this unless you really have to for whatever reason. Besides readability, another factor to consider is performance; Go is not optimized for functional programming structures. It doesn't have things like tail call optimization.

There's better languages than Go if you want to / have to do functional programming.

[stouset]

> you can't just know Go, you need to learn the ins and outs of this library too… before you can use it.

That is… literally just how libraries are. You need to understand the underlying language and the semantics and details of the library API.

[cle]

I believe these things are mostly productivity sinks, which is why I am such a Go fan and also so sad to see these types of projects in Go.

This is exactly what I was afraid of when generics were introduced, and now I get to spend time arguing with people who read some blog post about how functional programming and type theory will save the world, instead of actually being productive. Ugh.

[awused]

I think most of the stuff in this repo is too much and trying to beat a square peg into a round hole, but the little things like Option and Either patch a hole in Go. I don't think I'd use them without them being in the stdlib, though, which is where such fundamental types belong. Those aren't even really functional, unless you count null pointers as necessarily imperative.

>... read some blog post about how functional programming and type theory will save the world, instead of actually being productive

I see the opposite side in Go a lot, where without testing or trying anything they dismiss everything they aren't already using right now as useless ivory tower academia, which is its own set of popular blog posts. Seems both sides have a lot of time to argue on the internet though, oddly the people who actually write code tend to be the productive ones regardless of philosophy.

[_a_a_a_]

Do we have to do the "I don't really get it so nobody else should have it" kind of thing. I have a reasonable level of experience with FP and a lot of general experience (I'm not someone who "read a blog post", I've used it commercially) and I find that it's very handy at the right time. So it can be abused like anything else. So people can write over-complex stuff, true, so blame the language because it's easier than addressing the root problem which is people (it's always people isn't it). In a good language (Scala) it really makes a difference.

Please dial back your casual critiques.

> This is exactly what I was afraid of when generics were introduced

Good god. IDK, perhaps hardware would better suit your skill set? It certainly scares me off, but you might have a good mind for it.

[monksy]

I think you should realize is theres a mindset in go. They're highly opinionated about how you structure code, how you format your code (capitalization on all functions as a means to express public/private, tabs, etc), and how they want it to look. It's also designed to be basically a toy language to "make programming easier". They don't want language improvements like this for the most part.

The creator made it because: "The key point here is our programmers are Googlers, they’re not researchers. They’re typically, fairly young, fresh out of school, probably learned Java, maybe learned C or C++, probably learned Python. They’re not capable of understanding a brilliant language but we want to use them to build good software. So, the language that we give them has to be easy for them to understand and easy to adopt. – Rob Pike 1"

[_a_a_a_]

> They’re typically, fairly young, fresh out of school

Okay, thanks for clarifying and snakes and ladders is a great game for kids but how long do kids remain kids? They don't and they shouldn't. They don't need constraining for long.

> 're highly opinionated about how you structure code, how you format your code (capitalization on all functions as a means to express public/private, tabs, etc), and how they want it to look.

And as a professional programmer I couldn't give a toss about this, I just want people to be consistent and sensible, and that means useful comments, documentation, a test suite, specs, not going insane on any particular style like OO/FP. You have to trust the programmer in the end cos all the guidelines in the world won't cure stupidity.

[monksy]

I'm not sure how I'm replying to your message.

However the quote was made by the creator, not me. It's pretty frustrating that the justification and entire philosophy of the language surrounded is "we can't get better at this because it requires work" (Queue up the next few replies to me from people that say "but needless complexity and business value" )

> nd as a professional programmer I couldn't give a toss about this, I just want people to be consistent and sensible, and that means useful comments, documentation, a test suite, specs, not going insane on any particular style like OO/FP. You have to trust the programmer in the end cos all the guidelines in the world won't cure stupidity.

I agree with you. For the most part the industry has had expected language style guide lines (See the Java Style guide) and has had tools that support opting out of guidelines and defining organizational or project based expectations. This is not the case in Go. Gofmt will break your spaces decision and go to tabs. (https://news.ycombinator.com/item?id=7914523) Their response is they don't give a flip.

[_a_a_a_]

Okay, by stating their position I took it that you were supporting their position, which I see now was my misunderstanding. Gotcha, and thanks

[cle]

> Do we have to do the "I don't really get it so nobody else should have it" kind of thing.

Do we have to do the ad hominem thing? I studied FP and type theory in grad school. It's possible to know about FP and not want to use it in software engineering.

[_a_a_a_]

Okay, let's do it. ISTM you started the ad hom with loose accusations of people reading blog posts, ignoring that many people actually have solid commercial experience with it and are being "actually being productive" with it, nor did you justify your view they were "productivity sinks", so I couldn't take you seriously.

Then it got even harder with you dissing generics, which are so fundamentally valuable, such a labour-saver, that the idea of programming being better without them is beyond my ken.

So please lay out your case and I'd be willing to talk.

[earthboundkid]

I tend to agree. I’ve done a lot of JS and Python where I end up spending time doing functional tricks basically just because I’m bored and it makes things interesting. With Go when I’m bored I start profiling and making a zero alloc version of a function that only runs once a week.

[wheelerof4te]

FP totally works in Python...until you realize how slow function calls in Python are.

[goeiedaggoeie]

Feels like the spirit of Scala reborn.

[yoyohello13]

This is basically lodash all over again. Now I need to know two languages to read your code.