Idiomatic Generics in Go

Re:Idiomatic Generics in Go by bad_user on Tuesday September 30, 2014 @01:35PM (#8389609)

I personally like to think of simplicity as the opposite of entangled / intertwined, which is often at odds with easiness / familiarity. Rich Hickey has a very good presentation about it. I like doing that because then simple and easy are expressing 2 different things, both desirable but kind of orthogonal.

> overall simplicity and consistency matters more

Go took some good steps towards simplicity. OOP as present in languages such as Java is overrated and a primary reason for the complexity created.

We could use some variations for this need for ad-hoc polymorphism that we have. Unfortunately Go doesn't go far enough by not addressing the need for type-classes or something similar. And the language doesn't have to end up with a type-system as sophisticated as Haskell if you want type-classes. Clojure has a similar mechanism called protocols and yet it doesn't have OOP in the traditional sense, Scala has implicit parameters solved at compile time that can be used to model type-classes and overall type-classes are a simplification because they cleanly separate data from behavior.

Go also provides those channels as a more useful abstraction than plain threads. That's cool and all, but channels are not enough and a language should allow other people to evolve the language with even more abstractions for dealing with concurrency and parallelism, because there's no silver bullet. On top of the JVM people have built frameworks and libraries for actors, agents, csp, futures/promises, parallel collections, light-weight threads, STM, reactive programming / streams and most other things you can think of and the best a language can do is to allow evolution.

One should not confuse a small set of features with simplicity. Java was also a language that refused in the beginning to have generics and then in version 5 it got an abomination - as in generics that don't specialize for primitives and that solve co/contra-variance by means of use-site variance and freaking wildcards, instead of the much saner declaration-site variance. This happened because backwards compatibility is important and an established language needs to be evolved by providing a sane migration path. Go is slowly losing its window in which it can make bold changes.

Going back to your original point, a small set of features is bad if users cannot efficiently extend the language because the needed features aren't included. Having a small set of features is great, but it matters what those features are. I invite you to watch Guy Steele's "Growing a Language" presentation on this point, it's an astonishingly good presentation: https://www.youtube.com/watch?v=_ahvzDzKdB0

[ Parent | on HN ]

Re:Idiomatic Generics in Go by NateDad on Tuesday September 30, 2014 @02:38PM (#8390203)

Extending the language is exactly what the go authors and most experienced gophers don't want. I shouldn't have to learn your whole DSL / language extension to use or even read your code. Go intentionally disallows this so that everyone writing go is using the same language, rather than some subset, or god forbid superset, of the language.

[ Parent | on HN ]

Re:Idiomatic Generics in Go by bad_user on Tuesday September 30, 2014 @04:24PM (#8390928)

Well, it's a wonder that you're speaking English then, since English is routinely extended by means of new words and metaphors. Look, you just used "DSL" and "code", words part of a domain specific language that regular folks do not understand, plus "subset" / "superset" which require basic knowledge of set theory.

Besides, every time you create a new type or interface, you just extended your language with a noun or adjective and every time you come up with a function, you just created a verb. And I have to learn your nouns and your verbs to understand your code, even if you try explicit naming that don't really say anything (my personal favorite being variations on "processItems").

Go is not the first language to take this approach, it won't be last last either. Unfortunately people never learn and it feels like groundhog day, the movie.

[ Parent | on HN ]

Re:Idiomatic Generics in Go by NateDad on Tuesday September 30, 2014 @05:41PM (#8391466)

There's a difference between adding nouns and verbs, and changing the very structure of the language. If I say "I like to flargle my pofdin in a huffalop" you can still pick out the verb and the nouns, but if I say "#&_35( bar mdfsgh" you can't even tell if what I wrote is valid English.

[ Parent | on HN ]

Re:Idiomatic Generics in Go by bad_user on Wednesday October 01, 2014 @03:40AM (#8393251)

We aren't talking about changing the structure of the language, but about adding a feature to the language, generics, that would make it easier for people to build reusable libraries, especially libraries that treat functions (the verbs) as values that can be passed around, reused and still keep the static type safety of a language that is static.

Thing is, if you want a language without generics, then you want a dynamic language, because a static language without generics is overkill for building reusable stuff. Go's structural typing is cool and all, that's ad-hoc polymorphism done tastefully, but we are talking about a different kind of polymorphism here with different use-cases.

Watch that presentation, it's genius.

[ Parent | on HN ]

Re:Idiomatic Generics in Go by NateDad on Wednesday October 01, 2014 @10:25AM (#8394537)

When you said "a small set of features is bad if users cannot efficiently extend the language because the needed features aren't included" I assumed you meant something like operator overloading or macros or compile-time templates like in other languages. It seems like I was misunderstanding you. If all you meant was "a small set of features is bad if users don't have generics", then yes, my earlier response was not appropriate.

However, I would still have to disagree, given that I have written a lot of very useful code in Go, much of it quite reusable (without interface{} or reflection).

I did go click on that link and started to watch the presentation, FWIW. It's too long for me to watch now, but it definitely looks interesting, so I'll try to watch it in the next couple days. Thanks for pointing it out to me.

[ Parent | on HN ]