It's entirely possible for an expert programmer and pl designer to have never heard of ML-based languages or FP as a name for the concept.

Possibly. It's wierd he's so enamored with apl which just seems to me like languages focused an algebra designed around arrays.

Algebra based designs can be formed around many data structures and many languages generalize this concept like Haskell. With Haskell you can create your own algebraic DSL around arrays and anything else you can think of. It seems he's enamored with the specific array instance of algebra based designs and unaware of how it's only one specific case of a general concept.

APL wasn't originally a programming language at all. Ken Iverson designed it as a mathematical notation to express and reason about computer algorithms. "Notation as a tool of thought," is how he thought about it. It was implemented as a programming language years after he created the notation in 1960.

An APL-like Haskell DSL could be interesting, but to match APL's expressiveness you'd basically need to reimplement all of APL. For maximum generality, one could just skip both APL and Haskell and just use the lambda calculus. I found that a bit hard to work with, though.

As far as Numpy and all, they are all directly descended from APL. The only difference is that it takes 10 lines of Python to match 15 characters of APL. While the array languages' terseness can be excessive, doing it in Python is not very pleasant either.

Anyway, here's somebody who knows more than I do talking about what they like about APL's successor, J: https://www.youtube.com/watch?v=RWYkx6-L04Q

Is it? That seems like a very bold claim. MLs have been at the heart of a lot of language development for the last few decades, both as research languages for various concepts, but also practically: OCaml is fairly famous as a language to write programming languages in. FP isn't something wild and niche, it's discussed fairly regularly even amongst users of mainstream programming languages. Even Go has an FP library now, coming out of IBM of all places.

I don't think you can attribute this to ignorance, because it's very clear that Pike is not ignorant of programming language design - even if you disagree with his decisions, he has had tremendous success at implementing his vision. To me it speaks more of disinterest - FP doesn't seem to really register on his radar as a useful mine of PL ideas. That's fine, although I agree with the previous poster that it's ironic to be such a proponent if APL, and yet have such a blind spot to another very fascinating area of his field.

Would Haskel or some other functional language be a part of a typical CS curriculum?

I remember having a course about programming paradigms which introduced different languages and we wrote a small project based on functional languages.

it's hard to do theoretical CS without functional languages

I expect that in good universities, with rich curriculum.

At very least one of Lisp or Scheme variants, ML variants or Prolog variants.

Well, Lisp is just as functional as ML-family languages like OCaml and F#. Haskell's typed/pure FP is a branch off of this. Surely between Pike, Griesemer, and Thompson someone had some ML experience, but this doesn't matter much for the design of Go. More important is that newcomers can't be expected to have ML experience, and a central goal of Go is to be quickly accessible to new programmers. And there was also a focus on fast compile times, fast execution, and low-level control, which are very hard to achieve with immutable data structures. Overall Go's design is very restrained, which I think shows a lot of wisdom on the part of the authors. ML is not the only language slighted: as Rob says, the only bit of APL that made it in was the name "iota"!

I think it'd be a bit of a shame if everyone were pushed to be a polyglot with a finger in every currently popular paradigm. Connections between different approaches to programming are very useful, but the sort of effort made in Go, to refine and simplify one imperative/OO approach, also helps push our understanding of programming into new territory.

It's the whole (res, error) error handling thing.

Seems like there's an obvious solution that was avoided or not known about here. It's not even about being clever. Is about being practical.

Maybe so. I guess you're talking about option types, although it's not obvious to me that these do any better given the requirement that errors are always explicitly shown in the code. So maybe your problem is with that requirement instead. But why are you listening to a podcast in the hopes the guest will admit his ignorance and tell you something you already know, instead of to learn new things?

>I guess you're talking about option types,

I'm talking about a more general concept. A kind of type that can be either one thing or another. For example an Int or an Error.

You have Product types which are types that are two things at the same time an (int and an error) and you have sum types (int or an error). Mathematically the cardinality of the product type is (int * error) and the cardinality of the sum type is (int + error). Go is missing the sum type. It's like the world of math with only multiplication and no addition. It goes far beyond just Options.

For example JSON is not definable as a type in Go. Not without some really awkward stuff. You can define it in almost every other modern language:

Python:

   JSONTYPE = None | float | int | str | List[JSONTYPE] | Dict[str, JSONTYPE]

Haskell:

  data JSValue
    = JSNull
    | JSBool     !Bool
    | JSRational Bool{-as Float?-} !Rational
    | JSString   JSString
    | JSArray    [JSValue]
    | JSObject   (JSObject JSValue)

Rust:

  #[derive(Debug, PartialEq, Clone)]
  enum JsonValue {
      Null,
      Bool(bool),
      Number(f64),
      String(String),
      Array(Vec<JsonValue>),
      Object(HashMap<String, JsonValue>),
  }

You can define a type completely isomorphic to json in almost every language. You can't do that at all with Go. Literally this popular data format cannot defined in go. How the heck is that suppose to be "practical"?

What does go do when it comes to parsing json? I've seen it and it appears to be the ugliest thing I've ever seen. But that's another deep dive.

>But why are you listening to a podcast in the hopes the guest will admit his ignorance and tell you something you already know, instead of to learn new things?

I just got a job that involves golang and its now a big part of my life as it's now my daily driver. I thought due to the popularity of the language it must be great.

What ended up happening was Go feels like a broken language. But maybe I'm wrong. Maybe Rob Pike had a good reason not to include sum types in his language, or maybe he just didn't know about it. Imagine that, my life and the lives of other people defined by the fact Rob Pike didn't know something.

That's what I want to find out. Is the popularity of his language really stemming from him and other people not knowing any better? Or is it me not knowing any better? Have I not seen the light? Or have you not?

Sure, I've run into this when I went to do some language implementation in Go (dumped at [0]; didn't keep up with it just because I didn't have much reason to do it in the first place). I'd prefer ADTs, but I just frowned a bit and used interfaces. Your strong feelings here aren't because this is objectively inconvenient but because you think it's something you shouldn't have to put up with. If there's a factor you're missing—not saying there is—it's that types aren't supposed to tell the whole story in Go and it's fine to have data that's not fully described by a type.

I don't believe in a single "the light" to be seen. I know something you don't (the ability to create your own array DSL gives you none of the advantages of a particular array DSL developed over decades of hard work), you know something I don't. Go's popular because it got stuff right that other languages in the space like Dart and Swift missed.

[0] https://gist.github.com/mlochbaum/a7c0dcd482bd07f39fffc3332f...

> I know something you don't (the ability to create your own array DSL gives you none of the advantages of a particular array DSL developed over decades of hard work)

I don't see how this has anything to do with golang.

>you know something I don't

That go is missing sum types?

> Go's popular because it got stuff right that other languages in the space like Dart and Swift missed.

The only advantage I see are implementation specific and not language specific. Go has a better ecosystem, it's cross platform, it has extremely fast compilation times. The language itself is independent of these factors. You haven't mentioned any specific advantage by golang as a language here which is my main gripe with it as of now. But if you meant the implementation specific stuff than I agree with you, those are big advantages. It's one of the reasons why a language like python hasn't fully taken over... if python had the speed of C then it would likely even replace go.

Because of this I'm going to have to assume you agree with me. Go from a language design viewpoint is fundamentally broken. You clearly still like it, but you also clearly can't articulate specific reasons as to why. I mean this is normal, if you like something for really long and you learn that you've liked something flawed for years you're not going to flip around in seconds.

Anyway I think Go only appears fundamentally broken. There must be someone who knows why Rob Pike made these choices to leave our really fundamental primitives when designing go. I don't see why yet, and even though you're a supporter of go you haven't clearly elucidated why either.

I'm still waiting on the reasoning why Rob decided to leave out sum types and make go routines a first class feature when the concept of green threads are easily created as library sub rountines. Not being snarky here. I think this reasoning exists, we just don't see it yet. Perhaps someone else does?

I got curious and decided to google around. I din't find anything from Pike specifically, but my overall impression is that the maintainers simply refuse to see significant value in sum types. They do acknowledge the benefits but not their importance. Interestingly, the overwhelming majority of Go users (at least as indicated by this[0] GH issue) do wish for Go to have sum types. My speculation for Pike in particular though is that he's not that important to have significant influence on the evolution of Go.

[0] https://github.com/golang/go/issues/19412

JSON numbers are not floats/doubles.

> or maybe he just didn't know about it

They knew about it, they considered it, and they decided not to do it. Sometimes it's just that simple. It has been mentioned in the FAQ since day one: https://go.dev/doc/faq#variant_types

The key quote about go for me was that it was designed to stop google engineers trying to be clever, and clever FP/ML stuff was excluded explicitly

I remember this quote. The context of that quote was actually a reference to OOP and design patterns. He started talking about Nomenclature and referred to OOP Design patterns as just spending time creating taxonomy.

FP wasn't really referenced at all in that quote. FP definetely has it's own vocabulary, but nowhere near as extensive as OOP.

Previously: "[Pike is] hardly the first hard-core hacker to be ignorant of the degree to which type theory has seen dramatic advances since the 1980s." It's a comment on this quote from Pike: https://news.ycombinator.com/item?id=6821389

I think Pike definitely had not, at that point, explored the way types work in ML-style languages.