Go Blog

I see a lot of comments in here about the v2+ rule’s reason for existing being to allow importing multiple major versions of a module. That’s not it at all. As the blog post (which was easily Googled by me and explains things quite well IMO) states: “If an old package and a new package have the same import path,
the new package must be backwards compatible with the old package.”

They’re trying not to break compatibility until a downstream developer explicitly opts in to that breakage. The simplest way to do that is to give the module a new name. And the simplest way to do that is append the major version to the name.

Here is the post: https://blog.golang.org/v2-go-modules

For more background on this principle, I recommend Rich Hickey’s Clojure/conj keynote “Spec-ulation” from 2016: http://blog.ezyang.com/2016/12/thoughts-about-spec-ulation-rich-hickey/

In particular I know that Go's GC is optimized for very low latency (rather than throughput), and is not a stop the world GC. So I'm wondering why it doesn't work for games? Are the pauses still too high for games, or is he missing something? Benchmarks or concrete results in Go would be great here.

Edit: specifics from https://blog.golang.org/ismmkeynote - Go hugely improved GC latency from 300ms before version 1.5, down to 30ms, then again down to well under 1ms but usually 100-200us for the stop the world pause. So I guess it is stop the world but the pauses seem ridiculously small to me. They guarantee less than 500 microseconds "or report a but", which seems more than fast enough for game framerates (16ms for 60Hz frames). Am I missing something?

One good example is untyped constants. They form a large extension to the type system only present at compile time. It is a good example because there is an excellent blog post describing them in detail: https://blog.golang.org/constants

In particular note the difference between

const hello = "Hello, 世界"

and

const typedHello string = "Hello, 世界"

one of these can be assigned to named string types, the other cannot.

As a user of Go I find untyped constants to be extremely useful. They almost always do what I want without surprise. Implementing them however, is not trivial.

A tricker example is embedding. It adds a lot of complexity to the type system. As a user, it can be a bit surprising, but I admit it is very useful.

Which versioning scheme to use doesn't matter. What matters is how long you promise to keep a language "stable". Java and javascript have gone through many major versions, but the core of the language is largely stable. The same will be true to golang. Read their plan [1], the paragraph starting with "Go 2 must also bring along all the existing Go 1 source code". That is promised backward compatibility. There have been breaking changes in Perl5 (so it is not following semver), but most of the changes were minor and little user code was affected. Python 2=>3 is a disaster. If Julia goes through a dramatic change like that in 5 years, it will be worse.

[1] https://blog.golang.org/toward-go2

Source: https://blog.golang.org/toward-go2

> I don't believe Go 2.0 will ever happen.

"Once all the backwards-compatible work is done, say in Go 1.20, then we can make the backwards-incompatible changes in Go 2.0. If there turn out to be no backwards-incompatible changes, maybe we just declare that Go 1.20 is Go 2.0."

So yeah, Go 2.0 might not even happen.

> So far that page looks like when our government puts out "work commission" for any ongoing problem people complain about.

I would love if my government would take some inspiration from such projects, namely from this:

"We did what we always do when there's a problem without a clear solution: we waited."

One of Go's features is fast compilation, which wouldn't have been the case if it used LLVM.

> a GC which is competitive with JVMs from 15 years ago

I don't know where you got this impression, but it's absolutely wrong. Go's garbage collector is excellent. It has sub-millisecond pauses [1] (for multi-gig heaps), and it mostly runs in parallel to the application.

You might be referring to Go's old GC, which was dropped when the current was introduced. [2]

[1] https://groups.google.com/forum/?fromgroups#!topic/golang-dev/Ab1sFeoZg_8

[2] https://blog.golang.org/go15gc