In practice, it's used as an alternative to python and ruby and nodejs. It can't fully do what Java or C# do.
Go is a perfectly capable replacement for Java and C#. Many huge projects that would likely never be written in Python have been written in Go when they would have otherwise been written in Java or C# in years past: Kubernetes, Prometheus, HashiCorp Vault and Terraform, etcd, CoreDNS, TiDB, Loki, InfluxDB, NATS, Docker, Caddy, Gitea, Drone CI, Faktory, etc. The list goes on and on.
What, exactly, are you saying that Go can't do that Java can?
Go is not a perfectly capable replacement for Rust, for example, because Rust offers extremely low level control over all resource usage, making it much easier to use for situations where you need every last ounce of performance, but neither C# nor Java offer the capabilities Rust offers either.
I like C# just fine (Java... not so much), but your comment makes no sense. Certainly, I would rather use Go than most scripting languages; having static types and great performance makes a lot of tasks easier. But that doesn't mean Go is somehow less capable than Java or C#... it is a great alternative to both. If someone needs more than Go can provide, they're going to rewrite in Rust, C++, or C, not Java or C#.
Runtime library addition (plugins) and dependency injection are two big ones. (We can argue the merit separately, but they're not possible in Go)
I think if Java had easily distributable static binaries k8s would have stayed Java (it started out as Java).
DI is totally possible, just about every system I build is nothing but dependency injection. What confuses people in the Java world is that you don't need a framework for it, you just do it. You could say the language simply supports a simple version of it natively.
If you want something much more complicated like the Java way, there are some libraries that do it, but few people find them worthwhile. They are a lot of drama for what is in Go not that much additional functionality.
This is one of the many places the interfaces not requiring declaration of conformance fundamentally changes Go vs. Java and leaves me still preferring Go even if Java picks up every other thing from Go. You don't need a big dependency injection framework; you just declare yourself an interface that matches what you use out of some 3rd-party library, then pass the value from the 3rd-party library in to your code naturally. Dependency injected. All other things you may want to do with that dependency, like swap in a testing implementation, you just do with Go code.
(And I personally think that if Java's interfaces were satisfied like Go's, there would never have been a Go.)
Linux only, but it exists and it works… I just wouldn’t recommend that particular pattern for almost anything.
Either some kind of RPC or compile-time plugins would be better for almost all cases.
- With RPC plugins (using whatever kind of RPC that you prefer), you get the benefit of process isolation in case that plugin crashes, the plugin can be written in any language, and other programs can easily reuse those plugins if they desire. The Language Server Protocol is a great example of an RPC plugin system, and it has had a huge impact throughout the developer world.
- With compile-time plugins, you get even better performance due to the ahead-of-time optimizations that are possible. Go programs compile so quickly that it’s not a big deal to compile variants with different plugins included... this is what Caddy did early on, and this plugin architecture still works out well for them last I checked.
> dependency injection
Java-style DI isn’t very idiomatic for Go, and it’s just a pattern (the absence of which would not prevent applications from being developed, the purpose of this discussion)… but there are several options for doing DI in Go, including this one from Google.
I don't see anything inherit to Go that would prevent it. gc even added rudimentary support some time ago, fostering the addition of the plugin package[1], but those doing the work ultimately determined that it wasn't useful enough to dedicate further effort towards improving it.
There was a proposal to remove it, but it turns out that some people are using runtime library addition, and so it remains.
All that said, what makes your list any different than a similar list comparing Java to Blub? I don't see your list as preventing one from writing a Java app in Go using Go's idioms instead. (It can't fully do what Java or C# do.)
They're inferior, and do not cover the same grounds (e.g. "enums" in golang are just integer constants, you can't code gen using golang tags, JFR is way way more comprehensive than anything that golang has etc.)
The GC selection, JIT, and hot swapping/reloading are features that do not exist in golang, and we've seen what hoops people have to jump through when they face issues that can only be resolved by them. Basically, they're features most people don't know they need them until they do, then they'er already in a big mess.
You can write a Java app in golang or assembly, but it won't be anywhere near as maintainable, clear, concise, debuggable, or correct.
Of course you can code gen using Go's tags. It's done all the time.
As already pointed out, Go has the JFR it needs, not what Java has.
Go doesn't need a JITter.
Go isn't perfect, but neither is Java or C#. Go code is known for being maintainable and easy for newcomers to read so your last line applies to Java more than Go. But it seems like you want to hate Go. Why?
It does, I have to think twice because I know I'm not getting the compile time features that Java offers, and may end up just using strings in an awkward manner.
> Go has the JFR it needs, not what Java has
That doesn't make sense. All programs need the JFR that Java has, otherwise you wouldn't see companies like Datadog doing well.
> But it seems like you want to hate Go. Why?
I've used it in several large projects at my employer, and in every single project, Java would have been a superior alternative. We've had issues that would not have happened in Java due to many things, such as better error handling in Java, enum support, better frameworks and libraries to interact with the DB, etc.
And no, golang is not known for being maintainable, it's just things that some people parrot without proof. It's basically marketing. There's nothing in the language that inherently makes it more maintainable than Java/C#/etc., and in fact, it has many things that make it less maintainable.
It could probably use some performance optimizations, but JIT would be redundant when it's already compiled.
Nice-to-have (I've certainly enjoyed something similar writing JavaScript in a browser for years), but most developers aren't writing code under tight-enough constraints to justify a profiler running under a virtual machine.
I am curious, what all stuff it cannot do?