Hacker News new | ask | show | jobs
Go 1.27 Interactive Tour (victoriametrics.com)
108 points by Hixon10 3 hours ago
12 comments

This release also fixes runtime.findnull() to be compatible with MTE on Android ([1] and [2]). This was the only thing preventing MTE from being enabled for apps that use gomobile on MTE-compatible Android OS's like GrapheneOS.

[1] https://go-review.googlesource.com/c/go/+/749062

[2] https://go-review.googlesource.com/c/go/+/751020

Go's standard library has always been it's strength, especially the crypto package! Lovely stuff.
Automatically draining http response bodies is a risky silent behaviour change. I think it will be an improvement for most applications, but it's very subtle if you were relying on the old behaviour
Tried running a couple of examples in the tour, but ran into a few errors.
Tried reading your comment but ran into a lack of usable information.
Those Generics syntax in Golang seems so hard to read.
It is verbose but inference helps a lot to keep it “tidy”. I always find myself increasing my focus a notch when I start dealing with generics. It’s one of the things I use only if I really “need”.
Yeah, I agree with that.

Back when Go's generics came out, I was working with about 20% Go and 80% Python. I looked at the syntax, went "not today, Satan" and never bothered to learn it. For the past half year I've been in a mode where most of my coding time is spent with Go and I've been completely indoctrinated. I unironically like thinking about how generics and interfaces interact now.

I also need to slow down when I need to use them for non-trivial stuff. Not just relative to Go code but relative to how much I needed to think about them back when I was using OCaml. I think part of it is that I save them for hard issues and use interfaces for easy stuff.

Adding simd in std and even being used in map is nice. Would have to look for places to experiment with it in hot loops in code I have.
Some examples for the upcoming release https://go.dev/doc/go1.27
This is quite of a big release and I like the new methods on generics.
This level of generics actually has me interested a bit in Go now.
Can generics be used to improve error handling and eliminate the if err pattern?
No.

I kind of want to leave it there. But that will probably be looked on disfavorably.

I've seen at least a dozen attempts. It's not like it's hard to write it out. There's maybe a couple of variants but they're all just a handful of lines. The problem is, once you have an Option in hand, you end up trading:

    val, err := whatever(...)
    if err != nil {
        // handle error
    }
    // use val
for

    val := whatever(...)
    if err, isErr := val.Error(); isErr {
        // handle error
    }
    realVal := val.Value()
    // use realVal
What you win in nominal safety, you're definitely losing in convenience.

There's also no win in trying to offer a monadic interface like

    finalVal := whatever(...).OnVal(func (val Value) opt.Option[Result] {
        // use val
    })
because that's the minimal specification of an anonymous function in Go, so it's very inconvenient. Even if that was trimmed down, nested functions are still problematic in other ways. And you still have to unpack finalVal anyhow.

Really the solution is, install golangci-lint, turn on errcheck [1], use a pre-commit hook to make it a commit failure if golangci-lint fires, and that pretty much covers the problem in practice.

One of the problems with Option/Result/etc. advocacy... not the pattern itself, the advocacy... is that it is generally are presented, implicitly or explicitly, as if the alternative is C, with its errno and the need to not just check an error value, but remember to go actively seeking out errors constantly, making it easy to forget. But by modern standards, that's completely pathological.

If we rate error handling techniques on a scale from 1 to 10 (best), C here is a 1, and standard Option is maybe an 8 or a 9. The way Go does it is maybe a 6; it is completely true that you can neglect to handle an error (see errcheck comment in previous paragraph), but it is in your face that an error is possible, and that's really most of the problem. Putting Option/Result/etc. is not always a "go from 1 to 9" result. "Go from 6 to 8" is a much less impressive proposition, and the other inconveniences that come with it in Go tend to overwhelm the gain. I use errcheck all the time, and even in the Before Times when I was writing it all by hand it really didn't fire all that often. Especially if I exclude test code. In an AI era this hardly rates at all. AI never neglects the error.

Whether it does the right thing with it, now... that's another story entirely.

Read those error handling clauses if you're writing Go with AI. I really don't like what I've seen AIs do with them by default. What I've seen out of AI has been very thoughtless. Nominally correct in some weak sense, but thoughtless.

[1]: https://golangci-lint.run/docs/linters/configuration/#errche...

I think my opinion will be even more maligned: I like Java-style checked exceptions. It forces awareness of the error and a clean way to propagate it.
The thing that most annoys me in Java in that area is when a dependency throws an unchecked error that wasn’t even documented.

Thanks so much for that! Now I have no choice but to be reactive when something fails…

Am I the only one who’s absolutely shocked that Go finally is embracing generics?

Does anyone have a bit of an inside view into what changed in the perspectives of the language maintainers?

I’m not buying the “it took us 20 years to understand how to do it correctly” argument, as this is something you explicitly take into consideration when designing the language or not. And it was specifically not a part of language design, and is much harder to retrofit (backwards compatibility).

So what changed?

(I was on the Go team for ages)

Seriously, that's all it was. Just Ian alone proposed and rejected a half dozen of his own different approaches to generics. Finally a language + implementation plan came together that people all liked.

Nobody was ever opposed to generics that I saw.

If bug free binary search implementation can take 16 years, I am ready to buy generics implementation could take 20 years.

> In his landmark book The Art of Computer Programming, legendary computer scientist Donald Knuth noted that although the first binary search algorithm was published by John Mauchly in 1946, the first bug-free version was not published until 1962—taking a staggering 16 years to get right.

Took a few more years to get really bug free.

> Fast forward to 2006. I was shocked to learn that the binary search program that Bentley proved correct and subsequently tested in Chapter 5 of Programming Pearls contains a bug. ... Lest you think I'm picking on Bentley, let me tell you how I discovered the bug: The version of binary search that I wrote for the JDK contained the same bug. It was reported to Sun recently when it broke someone's program, after lying in wait for nine years or so.

https://research.google/blog/extra-extra-read-all-about-it-n...

> what changed in the perspectives of the language maintainers?

The original maintainers moved on to other projects and the new community maintainers came to a consensus through the proposal and governance process.

No, that's not accurate. The same core people were involved.
It’s also not true that because it wasn’t part of the initial design that it was harder to retrofit. I just don’t understand all this go bashing that happens on this site especially when so much is badly informed speculation. I guess it’s easier to tear something down.
Unfortunately nothing changed. They wanted generics all along.

The Go ecosystem was a delicate, special thing. It was a wholesale rejection of the malignant consultancy takeover of programming that had festered and spread for the previous 15 years. Introducing generics was a grievous error, and they just keep making it worse.

It used to be you could look at any Go code from any author and pretty much instantly understand it completely. That’s no longer the case.

It used to be you would work on a problem, just writing the code from top to bottom. No time wasted fiddling with abstractions you’ll never use. You’d grumble about it, but succumbing to the temptation was impossible. That’s no longer the case.

I have written Go for the past decade and completely, fundamentally disagree with this take. Go has always had a tendency towards limited exressivity, which created a strong dependence on interface{}, type assertions, and runtime bug’s that should have been compiler errors.

When I read these grumbling takes about how Go use to be so simple etc I imagine devs who would revel in all the features they were unable to implement because it would be too difficult in the language. Or devs who love typing and re-typing the same code over and over again, littering their code with switch cases and conditional logic while passing themselves on the back for avoiding “abstraction”.

and they're still worse than the 1970s state of the art lol
generics were a slippery slope. give it a decade and Go will be indistinguishable from c++
Not here against Generic methods, but I feel the Go team is in a mid-age crisis where they lack of new things to do to prove themselves. See their iterators mini-drama not long ago?

I feel the sumtype/emum/routine demanders should yell a little harder so Go team can find their purpose again.

> generics were a slippery slope. give it a decade and Go will be indistinguishable from c++

Lib boost will have conquered every language by then!!! :D

Jokes aside, generics are unusable in a lot of languages due to their syntax choices. In Go we kinda have the problem that there's no real templating and no real macros, so they're even harder to use.

But I agree somewhat, generics feels to me like an anti pattern in Go.

Also, the way the Go core/stdlib is written, it makes generics so unnecessarily painful to debug. Why they decided to have definitions like "~C" or "~[]S" is beyond me. No human knows what the resulting compile time error means. They should have named these things "Comparable" or "Slicable" or whatever is more expressive. Just stop with this stupid single letter shit.