I hate this type of non-productive comment.

"Why he picked Go" is beside the point. That was his personal choice, and it's of no concern to us if it was a good or bad choice when he made it.

What IS of interest to us, is his findings, ie. about how (non) fitting was Go for the kind of work he describes, and for what reasons. Because that can helps us access the language ourselves for such uses.

>Those days the biggest productivity difference that arises from language choice comes from the availability of libraries

Again, not true for his needs. For what he needed, core library built-ins have sufficed in Java (Set etc). As for Go, he did find 2 libraries implementing them, but he still wished for a good core implementation.

>The bit on poor performance is unconvincing because the source of the difference has not been identified.

No, but it's well known that Go lags behind the JVM, something even the Go team aknowledges and attributes to maturity of the compiler/GC.

Plus, from the writeup, he sounds like a thoroughly decent programer to not be able to code his way out of Go performance bottlenecks. Doesn't sound like the guy who can't use a profiler (and in fact, he points in his article that he DID use one).

>This kind of "magical" thinking about black boxes one doesn't understand is unfortunately all too common across software engineering.

Random rant unrelated to TFA.

On another note, I built an algorithm using a bitset. At first, I used one of the libraries the author linked, but then I saw that it was easier to just do the bit-bashing myself for my particular use case. It's not that difficult if you are familiar with C and C++ programming.

If, however, you are coming over from a language like Python, Ruby, and even Java to criticize Go is an easy thing to do. Those are very high level languages that protect you from needing to understand types. The object oriented parts of Java languages give you the ability to use polymorphism, which is not as straight forward in Go. You don't have a common base class. You only have interfaces. Trying to recreate generic structures and then blame the language for not having them is foolish. If you can't program without generics, stick with Java from the beginning. Or better yet, don't do a project in Go until you understand how to approach problems the Go way.

I happen to like Go for the very reason that you don't deal with generics. Seeing the types make it easier for me to follow as opposed to following a chain of inheritance. Getting rid of all the factory code trims my code down. This makes things easier to read when you are not the author.

Comparing Java's compiler to any other compiler is going to have predictable results. Java may have the best compiler out there.

Inheritance is overrated, and the factory pattern is often overused. Both of those happen with generics.

Generics have nothing to do with inheritance and the factory pattern. There are lots of languages that have generics but neither inheritance neither factories: SML, OCaml, Haskell, etc.

Inheritance makes generics harder, in fact, because type inference becomes undecidable in the general case.

Factories are basically a workaround for functions not being able to be freestanding (unattached to a class) in Java (the "kingdom of nouns"), a problem that Go doesn't have.

Where do I say such a thing? I'm saying that generics are both overrated and overused.

Factories are basically a workaround for functions not being able to be freestanding (unattached to a class) in Java (the "kingdom of nouns"), a problem that Go doesn't have.

Being the "Kingdom of Nouns" is kinda the point of Smalltalk/Objective-C style OO. (Though Alan Kay once famously said that when he thought of OO, he was not thinking of Java.) That said, while it is nice to have someplace to put functions, there are times when it's also nice not to be forced to attach them to a class. Not so sure it's a problem as much as it's just a particular approach with its advantages and drawbacks.

Where do you get that Factories are "a workaround for functions not being able to be freestanding?"

> Where do I say such a thing? I'm saying that generics are both overrated and overused.

It looks like that's what you're suggesting here:

> Inheritance is overrated, and the factory pattern is often overused. Both of those happen with generics.

---

> Where do you get that Factories are "a workaround for functions not being able to be freestanding?"

A factory is, conceptually, a function of some set of inputs that returns a new instance - which is, of course, exactly what a constructor is. Now, it's not always appropriate for a class to know every single way in which it might be assembled, so such responsibility is usually lifted out - the question is where to put it. We already have constructors, and those are functions, so it would seem reasonable that we could just write method similar to a constructor, place it in some other namespace (perhaps in a completely different package/module), and then pass that along to the component that needs to create these new instances.

For languages like Java, the problem is that functions are not first class - you can't directly pass along a method/function like (Conf -> SomeService), so instead, it's common to create some special type, like SomeServiceFactory. If, for comparison, you take a look at Scala/Haskell/C#/etc, you'll wont often spot /.*Factory/ anywhere, because a function (with the ability to close over free variables) is much more concise, and doesn't require defining new types (e.g. SomeServiceFactory, versus Function<Conf,SomeService>).

I think that, seen in this light, the practice of defining dedicated factory classes is a rather clumsy approach necessitated by the design of the underlying language.

> Inheritance is overrated, and the factory pattern is often overused. Both of those happen with generics.

Non-sequitur here. To me, it's clear that I'm saying that generics are overrated and overused. Your interpretation makes no sense!

For languages like Java, the problem is that functions are not first class - you can't directly pass along a method/function like (Conf -> SomeService), so instead, it's common to create some special type, like SomeServiceFactory.

Another non-sequitur here. Factory pattern was originally popularized in the GoF book as a way of providing an opportunity for polymorphism.

If, for comparison, you take a look at Scala/Haskell/C#/etc, you'll wont often spot /.Factory/ anywhere, because a function (with the ability to close over free variables) is much more concise*

Old hand at Smalltalk here -- over 10 years. You don't often see Factory classes in Smalltalk. We also have very easy and nimble closures over variables in the context they're defined. I still don't get what you're on about.

> Non-sequitur here. To me, it's clear that I'm saying that generics are overrated and overused. Your interpretation makes no sense!

Ok, now I understand what you're saying. As an aside, I would suggest that most people (as is evident in this comment thread) would not interpret your statement the way you intended.

>> For languages like Java, the problem is that functions are not first class - you can't directly pass along a method/function like (Conf -> SomeService), so instead, it's common to create some special type, like SomeServiceFactory.

> Another non-sequitur here. Factory pattern was originally popularized in the GoF book as a way of providing an opportunity for polymorphism.

I agree (re: polymorphism), but I don't think that contradicts what I'm saying; functions with parametric polymorphism (with support for {co,contra,in}variance) provide the same benefits of class polymorphism in this context.

> Old hand at Smalltalk here -- over 10 years. You don't often see Factory classes in Smalltalk. We also have very easy and nimble closures over variables in the context they're defined. I still don't get what you're on about.

You're absolutely correct. However, my point was that in statically typed languages, generics are conducive to favoring closures over factories classes and inheritance. But, now I realize that we were arguing two different things.

You are making the non-sequitur. His interpretation is the only one that makes sense. It is not clear at all that you are saying what you claim you are saying. You are in fact not saying anything like it. You are saying two things you don't like happen with generics, but that is completely false.

So you are trolling, and you still haven't pointed out such a rule.

How/why are they overused? How are they overrated? How can you claim there's any benefit to static typing but say generics are overrated?

No, both of those have absolutely nothing to do with "generics".

I like the fact that you are forced to look at the algorithm vs the class hierarchy. I like that you don't have to read through factories.

I do think that generics would be great if they found a way of implementing them, however, I do not think that you need generics in order to write this kind of project.

I've demonstrated this myself by comparing the goroutines example prime number generator to a similar version written using Python generators.

The python generator code was faster, but there was a hard limit to how many primes could be calculated this way; I hit the stack limit.

[Edit] Code & times: http://pastebin.com/CqkMcxdK

Yes, with the exception of that being a story about some random idiot with an axe to grind, and this being a totally competent guy, that goes into detail about what he did and how, what trouble spots he found etc.

I guess, it being a hired project, he can't share the actual code. But he provided tons of pain points, well articulated.

I think that person was just frustrated.

I like Java as well. It can be difficult to read the implementation when you are surrounded with classes. That was the point I was trying to make.

If you are thinking in generic containers and are programming in Go, you either chose the wrong language or need to change how you are thinking.

Lots of languages are not object oriented and still have parametic polymorphism. Like SML. In 1973.

>If you are thinking in generic containers and are programming in Go, you either chose the wrong language or need to change how you are thinking.

If you are repeating the same baseless assertion routed in ignorance, then you either chose the wrong forum, or need to change how you are thinking.

I really like the language, enough to use it and work around the lack of generics, but that's a glaring weakness. They need some way to enable container classes.

Channels are a way of queueing work, which is great for many use cases.

You can use mutexes and shared memory if your situation calls for it. For example, if I am doing a graph traversal concurrently, I can use channels to send the work to many listening threads as I traverse that graph synchronously.

If for some reason, I need to update that graph's representation asynchronously, I may need to use mutexes to lock the graph since the graph is now shared memory.

[1] http://concurrencyfreaks.blogspot.com/2013/11/stampedlocktry...

[2] http://mechanical-sympathy.blogspot.ca/2013/08/lock-based-vs...

The first set of JVMs did implement green threads, which are what goroutines are. Shortly thereafter most of them switched to red threads, aka real threads.

You can still find a few JVMs that use green threads, like Squawk.

https://java.net/projects/squawk/pages/SquawkDesign

Other than that, java.util.concurrent provides mechanisms to map multiple tasks to single OS threads.

Operating systems have been able to handle an order of magnitude more pthreads than that since the day pthreads were introduced.

To answer your question, yes: my own library, Quasar[1], provides lightweight threads for Java.

[1]: https://github.com/puniverse/quasar

But the major problem is that many of the Java bashers tend to criticise without knowing what is possible to do in the Java ecosystem.

    > Go's zoo of builtin data structures is really, really   
    > poor compared to Java.

https://github.com/cosn/collections/

That being said, I completely agree that the author chose the wrong language for the problem at hand.