Go: Support for Generic Methods
99 points
6 hours ago
| 8 comments
| github.com
| HN
kardianos
2 hours ago
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This is great. Will be useful for data access methods!

As for the detractors, from the first generics proposal this was called out as a "not now", not never. There were questions of implementation. They aren't a super large team, and they try to do things incrementally and do them well.

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tczMUFlmoNk
59 minutes ago
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> As for the detractors, from the first generics proposal this was called out as a "not now", not never.

What? The post quotes the Go FAQ as saying, "we do not anticipate that Go will ever add generic methods". There is also some similar discussion of the original generics proposal, with language like "then it's much less clear why we need methods at all". (I'm omitting some context, but I don't feel that it changes the meaning.) Those feel much closer to "never" than "not now".)

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kardianos
44 minutes ago
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I could be mis-remembering it. I didn't look up and src it.
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dude250711
2 hours ago
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Gophers are usually quite fast, perhaps an elderly turtle would be a better mascot?
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rob74
2 hours ago
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In day-to-day usage, the (fast) compilation speed matters much more than the (slow) implementation of new features.
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christophilus
1 hour ago
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I totally agree, but I'd go further and argue that slow implementation of new features is itself a desirable trait. It's one of the reasons why why I like both Go and Clojure.
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aktau
1 hour ago
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Spot on. Heaven forbid it turns into a C++ (I'm not a Rust practitioner but from the outside it seems to accrete features pretty quickly as well).

The ease of grokking Go (both reading and writing) are big advantages, and facilitated by the "small" feature set of Go.

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mackross
33 minutes ago
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What a happy surprise today! The amount of times I’ve had to do weird janky package APIs so the API was still reasonable is more than I can count.
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nasretdinov
2 hours ago
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Lack of generic methods was really surprising to me when I was first trying to use generics in Go. Nice to see it being actually implemented
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ncruces
1 hour ago
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To be replaced by the surprise when you figure out these methods don't implement interfaces.

Still, in this case, half the feature is better than none at all, IMO.

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nasretdinov
33 minutes ago
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Generic interfaces are going to be implemented later too if I'm reading correctly. So no real surprises there :). I guess the only surprise yet is that generic interfaces aren't supported, so generic methods physically can't satisfy any interface
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h1fra
3 hours ago
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slowly implementing all the things they said we didn't need
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CamouflagedKiwi
2 hours ago
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They didn't say they never wanted to do generics, but that they did want to take their time and do them right.

Debatable how much they have been "right", although this gets them somewhat closer. And I think they have not been "wrong" in the ways they wanted to avoid (they referenced some issues with Java generics as prior art, although I forget the details).

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tines
37 minutes ago
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From another commenter here:

> The post quotes the Go FAQ as saying, "we do not anticipate that Go will ever add generic methods".

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TheChaplain
3 hours ago
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It's not a bad thing to realize that one can be wrong and then strive for change.
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a-french-anon
3 hours ago
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Maybe, but personally I've become quite tired of programming languages "organically grown" as opposed to properly designed the first time. After a good decade of C then C++, I found ANSI CL (despite being a massive compromise and unfinished) much more coherent and complete than both.
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bbkane
2 hours ago
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I know Go is justly criticized for many of its design decisions, but it still feels well-designed and "small" to me in day to day usage when many other languages don't.
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a-french-anon
1 hour ago
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Eh, the thing with generics coming late is pretty much what I meant by "organically grown".

My best litmus test these days is support for multidimensional arrays because it's always needed at some point in general purpose languages. CL and Ada had it right from the start while C++ needed C++23/26 to get std::mdspan and we still need to wrap it to pass the underlying/owned memory pool around (https://rosettacode.org/wiki/Multi-dimensional_array for more).

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nish__
31 minutes ago
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Doesn't every language support multidimensional arrays? It's just an array of arrays, no? What am I missing?
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pizza234
25 minutes ago
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It isn't realistic to expect a design to be "proper in first place" because requirements change; my opinion is indeed the opposite - I find it natural for programming languages to have a (sort of) lifespan, and for new ones to (sort of) take their place.
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xscott
2 hours ago
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Scheme is (or at least was) coherent. You don't need to look any further than set/setf/setq to see that Common Lisp is "organically grown" from the fertilizer of a committee. CL does its best to make every other lisp more attractive.
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rootnod3
2 hours ago
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Which Scheme are we talking about? R5RS? R7RS-small? R6RS? With SRFIs? Without? Which scheme? Is it `(library...)` or `(define-module...)`?
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xscott
2 hours ago
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Heh, I'd probably take R4RS with define-syntax :-)
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rahen
1 hour ago
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Scheme has a coherent and minimalist design, but its ecosystem and abstraction facilities feel too sparse for large applications.

When I started building a Lisp-based machine learning framework, Guile seemed like the right choice because it provides GOOPS and generic functions, yet I still ended up with a lot of boilerplate to compensate for the lack of a strong type system.

Scheme feels to me like C is to C++: not ergonomic for large-scale application development. Go is one of those languages that has both minimalism and productivity.

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ndr
2 hours ago
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"Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp."

-- Greenspun's tenth rule

He had some lack of conviction to scope it so narrowly.

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ramon156
3 hours ago
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So which language had it right from the start? is there a language that has a very low rewrite status?
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poncho_romero
45 minutes ago
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I think Elixir is a good candidate here. It's small, coherent, and composes well, and (at least to my understanding) the authors consider the language finished, with no new major features planned.
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bbkane
2 hours ago
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I'd particularly like examples of statically typed languages that "got it right" (since I love me my types)
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galangalalgol
2 hours ago
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Ocaml maybe? Multi threading didn't seem necessary and introduced the possibility of data races.
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maccard
2 hours ago
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That’s whataboutism - no language is perfect, but given when go released it’s fair to hold them to a higher standard than languages what were designed 25 years earlier.

As an aside - D, Zig, Rust, even typescript got most of the lessons learned from C right

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Maxatar
36 minutes ago
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D literally can't even maintain backwards compatibility between minor version updates not to mention a big part of the D community left when D reinvented itself with D2. Among languages it's probably the one that is constantly in a state of flux.
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blanched
1 hour ago
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I'm not familiar with D, but Zig and Rust are well-known for continuously evolving.

Zig has the (in)famous "Writergate": https://github.com/ziglang/zig/pull/24329

And besides Rust's high count of RFCs, there are things like async (I'm not complaining about it, but its an obvious large-scale "change"), module system changes, etc.

(To be clear, I like both languages a lot. But I wouldn't call them slow moving or right from the start.)

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iosjunkie
1 hour ago
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"properly designed" - ah yes, programming languages are famous for universally agreed upon design philosophies.
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rootnod3
2 hours ago
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ANSI CL is such a breath of fresh air nowadays. Does what you need, doesn't get in your way, comes with batteries included. And conditions are just god-tier.
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fhn
43 minutes ago
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so make your own and let's see how you do
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rootnod3
5 minutes ago
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Have you?
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boxed
2 hours ago
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I liked Objective-C (except the C parts). Such a breath of fresh air coming from C++ which was grown like a cancer with tons of features and you felt trapped by every one of them.

Objective-C in contrast was a very few additions thoughtfully added that composed cleanly and freed the programmer to actually get things done.

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maccard
2 hours ago
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There’s a fine line between being willing to change your mind and getting the basics wrong. Go has repeatedly gotten the basics wrong.
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whoiskevin
2 hours ago
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Declaring a highly successful language as having the basics wrong means that you are not correct about the basics that were needed.
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maccard
2 hours ago
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Something can be highly succesful in spite of having glaring design flaws. Nobody is claiming go isn't wildly succesful, but it's _in spite_ of these issues. It was clear over a decade ago that iota, gopath, and lack of generics were massive kneecaps to the language; go changing it's mind on those things isn't progress it's just getting the fundamentals wrong.

A good example of where they're kind of stuck is date formatting - it's stupid, unclear, and likely a mistake, but it's not a fundamental flaw; it's just a quirk.

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9rx
2 hours ago
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Why is iota a massive kneecap to the language? It is semantically identical to enum in C and Typescript.

The trouble is that Rust is older than Go and it was already confusing people into thinking enums and sum types are the same thing, so by using slightly different syntax, iota, Go avoided the whole confusion of users thinking that enums would behave like sum types instead of actual enums.

Is your attempt at making a point that not having sum types is the massive flaw? Sum types are a useful construct, to be sure, but there are plenty of good languages without them. That's more on the design quirk end, realistically.

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maccard
1 hour ago
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> Why is iota a massive kneecap to the language? It is semantically identical to enum in C and Typescript.

iota is a massive kneecap _because_ it's semantically identical to enum in C and Typescript.

> Is your argument actually that not having sum types is the massive flaw? Sum types are a useful construct, to be sure, but there are plenty of good languages without them. That's more on the design quirk end, realistically.

In a dream world sure we'd have full blown sum types (and that would give a result type which would also solve a lot of the nil-interface-combined-with-error-handling issues that I've ran into when working with go), but I can forgive that. The problem is this - https://www.zarl.dev/posts/enums

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jolux
1 hour ago
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Rust is technically older than Go, but who was actually using it when Go 1.0 came out in 2012? Rust 1.0 wasn’t until 2015.
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9rx
1 hour ago
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The social landscape doesn't depend on anyone actually using it. However, 1.0 isn't a significant milestone like you suggest either. For a current example, Zig is relatively popular today despite not yet reaching 1.0.
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n6242
1 hour ago
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By that logic Windows would be the best operating system ever and perfect in every way, and anyone who disagrees must be wrong about how an OS should be.
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hocuspocus
1 hour ago
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And Javascript and Python the best languages.
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jeswin
2 hours ago
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It's a highly successful language because (1) it was backed by Google, and (2) created by Robert Griesemer, Rob Pike, and Ken Thompson.

If it came out of anywhere else, it might have struggled even to hit the homepage here.

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amazingamazing
2 hours ago
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This logic is easily shown to not hold. Why isn't Carbon, Dart, etc. not really popular then?
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doodpants
47 minutes ago
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I can't speak about Dart, but Carbon had just barely started development when it was first announced 4 years ago, and is currently presented as an experimental language that is not yet ready for use [0].

0: https://github.com/carbon-language/carbon-lang#project-statu...

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voidfunc
1 hour ago
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Its just bitter dorks bitter their pet language with cutting edge programming abstractions didnt make it to the big leagues.
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boxed
2 hours ago
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The basics of a programming language were wrong. The basics of marketing were very right. Those are not the same.
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9rx
2 hours ago
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An engineer, of course, understands that there is no such thing as "wrong", only different tradeoffs, but with the rise of "vibe coding" you don't need to be an engineer to play in the world of programming anymore.
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OtomotO
1 hour ago
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cough JavaScript cough
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Jleagle
2 hours ago
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Sounds like you want this feature, and you just got it. Not sure how that's wrong. You don't add in every feature from the start.
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maccard
2 hours ago
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I wanted it 10 years ago.
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tux3
2 hours ago
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I don't think anyone admitted any wrong or had any big change in philosophy. It's always a good thing to learn something along the way. But the current message seems to be that this was the plan all along, and it just took some time to design properly.

Of course adding generics is not something that every language needs to do. Scripting languages like Ruby don't really need this style of generics. It doesn't fit the design of the language, and it's not even clear what that would look like in Ruby.

But static typing with generics does solve a recurring problem, and we've seen some real convergence towards type hints and type systems even in staunchly dynamic scripting languages. Modern Javascript is now mostly Typescript, and they've successfully retrofitted a very advanced type system in the last place I would have expected 20 years ago.

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galangalalgol
2 hours ago
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Type hinting seems like the worst of both. You pay the cost on refactor to go change them all, where dynamic typing or static type inference avoid that. You also don't have any of the benefits of static or dynamic typing. My strong preference is static typing with good inference and an ide that shows the inferred types everywhere when asked. Dynamic typing can make some tasks dramatically easier, I'm just not capable of using them without making hideous mistakes.
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layer8
2 hours ago
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It’s still annoying ~20 years after Java did the same mistake of not including generics, which was already clear to many people with C++ experience back then.
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Cthulhu_
1 hour ago
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Where did "they" say "we" didn't need generics? That sounds like a bad faith / misinterpretation / straw man; as someone else pointed out, they postponed generics until they figured out the use cases and whatnot.

Remember that the generics implementations in other languages (like Java) take up half the spec + implementation - that's not something that Go wanted.

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tines
37 minutes ago
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From another commenter here:

> The post quotes the Go FAQ as saying, "we do not anticipate that Go will ever add generic methods".

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9rx
2 hours ago
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Of course, if you go back and watch the original Go announcement it said that it would need generics once they figured out how to do it. And when the first version of generics landed it was said that generic methods would be added later, once they figured out how to do it. So that isn't applicable here. The need was always recognized.
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fhn
56 minutes ago
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complaining about things given to you for free
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doodpants
37 minutes ago
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I frankly don't buy into this trope that a lack of monetary cost should shield something from criticism. Anything created by humans for other humans, especially tools meant for getting work done, should certainly be open to evaluation/judgement/critcism, regardless of whether the creator chooses to charge for it.

And it's not like Golang is some freshman student's hobby project; it was created by one of the world's largest tech companies, by people with a strong pedigree in programming language design.

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samber
1 hour ago
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OMG. I'm going to recode some of my libraries.
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reactordev
2 hours ago
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This resolves a big gap in generics for most people coming from other languages to go so I completely approve this direction. Not saying use it everywhere but if you must use it, it’s better to have it on the struct than call a module level generic func.
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binary132
2 hours ago
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Chasing a perceived gap between language features and user expectations has been and continues to be the greatest error in the leadership of Go.
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pizzafeelsright
29 minutes ago
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The nagging imperative requires a stronger response than the capitulation of identity.
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throwpikerob
1 hour ago
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A sad day for Go, the pHDs have won, simplicity has died.
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valyala
1 hour ago
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Cthulhu_
1 hour ago
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It only died if you actually applied it in your own codebase - as with any feature, using it is optional.
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