[dekhn]

No, the authors specifically said that they would like to have generic features but couldn't figure out a way to implement it without unacceptable performance problems.

I'm pretty sure the feature will show up in the next few minor version increments.

[aikah]

> I'm pretty sure the feature will show up in the next few minor version increments.

No it won't. People need to stop expecting generics because it will never happen. Not that agree with this but it was made pretty clear in the go-nuts mailing list that the Go team wants to keep Go type system "simple".

[nsajko]

Maybe in Go 2? ;)

[MikeTaylor]

Never gonna happen, Go 2 is considered harmful.

[api]

This is one of the things I like about Go: it's "done." In exchange for passing on extensions that might make certain use cases easier, we'll avoid the bloat and have decades of backward compatibility.

We just came out of a decade of nifty language mania. What I learned is that languages are boring but problems are interesting. Algorithms and solutions are interesting. A great solution to a challenging problem is really interesting even if it's in the most boring language ever.

I have code on my machine written in C in the 70s because C is largely "done." People today continue to write interesting stuff in C. Neuromancer was written in the same language as Lord of the Rings and Moby Dick, too.

[yokohummer7]

C is clearly not done, actually. Both C99 and C11 added, deprecated, and even removed many features. You can run C in the 70s not because it didn't change, but because it retained backward compatibility. It will be pretty surprising if Go manages to prohibit even the same level of changes C has taken.

[zeckalpha]

What C compiler do you use to compile that 70s code? I find modern compilers usually choke on the "done" C code from then.

[jschwartzi]

You have to feed it a switch or two, but gcc will do it.

Of course, we're talking about pre-ANSI C where any function prototype without a void argument implicitly accepts any and all arguments.

[JonahBraun]

You missed the joke re: Go 2.

I don't think Go is done. The active development speaks otherwise.

[MikeTaylor]

I think everyone missed it. Glad you, at least, didn't :-)

[MichaelGG]

Basically they dismissed every implemented approach, despite generics obviously working in other systems. (And it's hardly a "new" feature unless we're counting in multiples of decades.)

[AnimalMuppet]

> Basically they dismissed every implemented approach, despite generics obviously working in other systems.

But working at a price. And Go isn't willing to pay the price (especially in terms of compile time). If Go ever adds generics, it will be with a new approach that doesn't blow up compile times.

[MichaelGG]

C# compiles and JITs incredibly fast and has generics. F# has the same generics and compiles far slower. The reason isn't compile times. (Especially since one impl of generics is just generating code, which is cheap.)

IIRC the reasons on the list were the standard tradeoffs of memory space and so on. Do they emit specialized versions for each function, or not, and so on. Again, stuff that's working fine in other platforms.

[gnuvince]

A few years ago, Andrei Alexandrescu showed that the dmd compiler was actually faster than the gc compiler, and D supports templates. Recently, with 1.5, Go has shown that it is ready to take a hit on compile-time speeds. I don't think the argument of compilation speed holds for generics. To me it sounds much more like a culture thing: generics, for better of for worse, add an extra thing to think about and I think that the Go authors and many Go developers are just not interested.

[15155]

I wonder how much developer time is spent due to a lack of generics.

Developer time costs more than compiler time.

[AnimalMuppet]

> Developer time costs more than compiler time.

I find that to be a very odd statement. Usually, the developer waits for the compiler in order to find out if the code compiles and executes properly. That is, every minute of compiler time costs a minute of developer time.

Worse, the developer time you spend due to lack of a feature, you spend while writing some code that would benefit from the feature. The compiler time you pay every time you compile - year after year, for some projects.

[lmm]

> I find that to be a very odd statement. Usually, the developer waits for the compiler in order to find out if the code compiles and executes properly. That is, every minute of compiler time costs a minute of developer time.

If your business starts to hit a wall on compile times you can buy a computer that can compile twice as fast. It's much harder to buy a developer who can think twice as fast. And every year the computers get faster and the developers stay the same.

> Worse, the developer time you spend due to lack of a feature, you spend while writing some code that would benefit from the feature. The compiler time you pay every time you compile - year after year, for some projects.

No, the cost of being unable to abstract increases exponentially as your system grows. If using language X lets you cut 500 lines from a 1000-line Go project, then when you have a 2000-line Go project, in language X you'd be able to cut 500 lines from each half of it considering each half in isolation - and then you'd be able to cut some more because of things that were common between the two halves - so you'd end up with just 750 lines of language X. And you pay the cost of extra lines every time you read or debug, year after year.

[blt]

> If your business starts to hit a wall on compile times you can buy a computer that can compile twice as fast.

Buying a fast machine only gets you so far. Large C++ projects take minutes to compile even on the fastest machines available. Plus, you'd need to buy one for every developer.

> when you have a 2000-line Go project, in language X you'd be able to cut 500 lines from each half of it considering each half in isolation - and then you'd be able to cut some more because of things that were common between the two halves - so you'd end up with just 750 lines of language X.

While this is true in theory, in practice I think the effect is not quite as large. As the project grows, developers take ownership of certain parts of the code and become ignorant of other parts. This is the whole point of abstraction. Under these conditions it will take a heavy investment of time and effort to find and replace the things in common between the two halves. So you might cut 250 lines in common between two 1000-line halves, but you're not going to cut 25,000 lines in common between two 100,000-line halves without a serious amount of work.

I think Go's design shows awareness of this effect. The Go literature does not preach the battle against code duplication as strongly as, say, Java. The goal is to make it easy to understand the other team's 100,000 lines, even if that comes at the expense of some code duplication.

Note: I am not a Go programmer, but I do think that optimizing for ``code entropy'' (lack of duplicated code) over all else is a mistake.

[tracker1]

It depends on the use case... C# is a wonderful language, since the addition of generics and lambdas, it's downright beautiful to work with. But this does come with a cost... Even a simple hello world console app has a pretty significant spin up time compared to go, or anything that is truly compiled.

In some cases, if you have long-lived services, then Java and .Net make sense... You can get farther with the code in place. If you are running one-off executable handlers, that need to start and finish quickly, then you probably would favor go.

It's entirely possible for different options to be part of a larger solution.. and while I agree, the lack of generics is truly painful... I remember C# before, and feel that Java's generics are a horrible implementation... I'd rather wait for a nice implementation just the same.

[15155]

> Worse, the developer time you spend due to lack of a feature, you spend while writing some code that would benefit from the feature. The compiler time you pay every time you compile - year after year, for some projects.

Except that this is a false dichotomy: you don't have to have a lack of features to get a fast compile. Incremental compiles have existed for a very long time in various language ecosystems and will achieve very acceptable results.

In addition, SSDs and multicore CPUs can be leveraged to decrease compile times, and these things are only getting better.

[staticint]

I imagine not that much in practice. It is not like someone is going to manually write out identical functions twenty times for each type they want to support. That's precisely what computers are good at doing and there are countless tools to do it painlessly.

The bigger problem is that Go doesn't have type inheritance or similar. Meaning, there's no great way to say that this generic function will only work with number types, for example. You leave the burden on the programmer to ensure their generalized function is applied only to types which it is intended to be used with.

While that is less than ideal, I cannot see that increasing developer time by a significant margin.

[15155]

> It is not like someone is going to manually write out identical functions twenty times for each type they want to support.

I'll stop you right there. Have you seen a modern Go codebase?

They most certainly duplicate the simplest of functions, resort to `go generate`, or use reflection.

[staticint]

I am afraid I am not entirely sure of what you are trying to get across here. Your mere mention of go generate indicates to me that you do understand my point about computers being able to free the programmer from doing the drudgery of implementing the same generalized function twenty times. And since you are familiar with go generate, I expect you also realize there are seemingly endless tools that exist to solve this specific problem.

I _think_ what you are trying to say is that templates in Go are less convenient than in some other languages. That is a completely fair assertion. But the idea of having to type `go generate` occasionally adding significant man hours to a project seems a little far fetched. You could even:

  alias go='go generate && go'

I completely understand the appeal of templates/generics being a first-class language feature. Not even the Go authors themselves discount the usefulness. I don't understand why the lack of them is adding so many more man-hours to your projects? The overhead of working around the lack of them should not be that significant, even if less pleasant.

[xrstf]

Which is why Go is advocating using "go generate" to generate code. See projects such as https://clipperhouse.github.io/gen/

[masklinn]

A fantastic idea, even slower to compile (since you need to parse extra source files), more complex workflow, and extra files which developers have to remember to ignore.

[yokohummer7]

This is exactly the case that the problems of a language are solved by tooling. This attitude can be easily found in the Java ecosystem, where the answer to every question is "to use IDE". Interestingly, Java recently abandoned the idea of feature stagnation and started improving the language. I'm curious when this will happen to Go.

[AnimalMuppet]

Slower to compile, but starting from a much faster starting point.

[dekhn]

I'm not even aware of go compiling most of the time (it's typically under 1 second). go's build system handles these sort of things without a more complex workflow.

[geon]

Slow compilers waste developer time.

[15155]

Incremental compiles have existed for quite some time.

Go is only unique in that it can do a complete recompile in very attractive times. The only hitch, of course, is that you sacrifice features known and loved in other languages for over a decade.