[npalli]

That's interesting. I had the opposite reaction regarding Golang capabilities while following this saga. Not sure how 'idiomatic' the Golang code is, at first glance it just seems less expressive (more lines of code) than either c++ or java!. I didn't think that was possible.

So whenever people talk about expressiveness of Golang it just seems like a design gone bad. The designers wanted a programming language with the expressiveness of python and the speed of C, they ended up with a language with the expressiveness of C and the speed of python.

[pbsd]

I agree, I honestly don't see where the expressiveness claims of Go come from. I've always put it in the Java-like bin of languages (which is not necessarily a bad thing).

I suppose the one thing that Go does well (compared to C++ or Java) is builtin concurrency and communication across tasks.

[tptacek]

My first impression of it was that it was like a cross between Java and Python. It is unmistakably similar to Java conceptually and syntactically; they are sibling languages, both designed to streamline, simplify, or modernize C.

I'm a Java-literate C/C++ programmer. I would avoid writing straight Java code at all costs; I find it immiserating. Here are some reasons off the top of my head that Golang is more pleasant to work in:

* The syntax is deliberately streamlined, including implicit declarations, semicolon insertion, lightweight expression syntax, the capital-letter-exports-a-symbol thing

* It has fully functional idiomatic closures

* Interfaces get rid of adapter class BS

* The table type (maps, in Golang) is baked into the language, like Python, not a library, like C++ and Java

* Clearer, more direct control over memory layout; data structures in Golang feel like C

I don't know if Golang's standard library is that much better than Java's, but it was obviously designed carefully by and for systems programmers, so I find it remarkably easy to work with.

It also feels like a much smaller system than Java. Almost every time I write a significant amount of Golang code, I find myself answering questions by just reading the standard library source code. It's easy to get your head around. I've written compiler/runtime-level code for the JVM and I still don't have a great grip on all of Java.

[georgemcbay]

I agree with all of the above and I write Java code for a living currently (Android/Dalvik though, not for the JVM).

Another cool aspect of the last point (Go being small and lightweight) is that if you've got gcc and mercurial on a supported platform, building latest go from source is as easy as:

hg clone http://code.google.com/p.go cd go/src ./make.bash

Got to build a local copy of the JVM and/or JDK for some reason? Good luck with that (even ignoring all the licensing, OpenJDK vs closed, etc)

[lmm]

Have you compared it with ML or Haskell?

[RamiK]

Brevity and expressiveness are not the same.

[yohanatan]

Are you sure about that? Given that any [Turing-complete] language feature can be implemented in any other [Turing-complete] language, the only conceivable difference is in fact length of implementation.

In other words, it is possible to express anything in one Turing-complete language that is possible to express in another.

[hetman]

Except my brain isn't a Turing machine. What expressiveness means then is how easily I can fit the concepts of the code in my head (not on my harddrive). This is not the same as how short the code is, though the two are often closely related.

[yohanatan]

Expressiveness is power and it applies to the act of writing code, not reading it. I agree that it is ideal if one's code can be read and comprehended easily by others although that has little to do with expressiveness.

http://www.paulgraham.com/power.html

[cgag]

To me, expressiveness is about expressing an idea with as little incidental complexity as possible, which is definitely different from as in as few characters as possible.

[yohanatan]

I don't think it is different actually. 'Kolmogorov complexity' (which is essentially the global minimum 'essential complexity' of a particular algorithm) is specified in terms of length.

[fauigerzigerk]

Applying Kolmogorov complexity in this context is a bit more tricky than you make it appear. Kolmogorov complexity measures the complexity of a string as the length of the shortest possible program that generates that string.

So to measure the complexity of a program P we have to write another program G that generates P and then take G's length. It's not a given that a generator for a verbose language is necessarily longer than a generator for a terse language.

But more importantly, what we want to measure is the mental effort required to write and understand code in different languages. To measure that effort in terms of Kolmogorov complexity, we'd have to write a program that generates our states of mind while programming.

Good luck with that ;-)

[kvb]

See Felleisen's "On the Expressive Power of Programming Languages"[1] for one formalization that differs from conciseness. Essentially, Turing complete languages can express the same programs at the very coarse "whole program" level, but the paper advocates taking a more local view to assess expressiveness (e.g. what programs in L1 can you write in L2 without having to do a whole program transformation). See also Neal Gafter's related commentary[2] (in the context of the various proposals for closures in Java).

[1] http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.51.4...

[2] http://gafter.blogspot.com/2007/03/on-expressive-power-of-pr...

[yohanatan]

One doesn't have to look far before he finds a fatal flaw in the commentary. Particularly this:

"In my mind, a language construct is expressive if it enables you to write (and use) an API that can't be written (and used) without the construct." - Neil Gafter

Once more, there is no such construct. All APIs can be written and consumed without language support. Otherwise, Boost would not have had all the new C++ goodies (as an add-on library) before they became part of the language itself. And, of course, one can always put the 'human compiler' to work to produce boilerplate that would be produced by the compiler if the language in question supported the feature in question (if there isn't an add-on library providing the feature in question). One can always do this but the discriminating one tries to avoid it and instead chooses 'expressive' (i.e., conciseness-facilitating) languages. [In the case of closures in Java, one [human-compiler] would merely use one-off interfaces or anonymous classes].

I will take a look at the other links but I gave up on the commentary after seeing such a blatant falsehood.

[kvb]

C++ has features like operator overloading that make faking lambdas via Boost feasible. And even Java has anonymous inner classes that allow a rather ugly local transformation somewhat akin to closures. But if you removed that feature, then you'd need a non-local transformation to fake them.

[cmccabe]

Are you sure about that?

Yes.

[yohanatan]

You can be sure if you want but unless you back up your claim with some reasoning, others will consider you wrong.

[CCs]

A line from a real code (a library):

    "* ^^"._? #> (a.!?(1, Get())) must be_==(Full(Answer(1))) ?~! eventually

It is very short, most of the people would implement the same thing using 5-10 lines of code. I prefer 5-10 lines of code over regex-like syntax.

[cmccabe]

"Brevity and expressiveness are not the same."

"Are you sure about that?"

"Yes."

Do I need to explain?

[charlieflowers]

He gets points for brevity. You gotta admit that :)

[cgag]

I'm not sure if it's because the JVM has a bad rep or people like the familiar feeling of Go (smaller learning curve) or some other reason, but it surprises me so many people jump to Go for performance similar to what you'd get on a modern JVM language (Clojure, Scala), but with less expressiveness, fewer libraries, and (I believe) less tooling.

Of course this only really applies to long running apps (web servers), if startup time matters then certainly Go wins.

Perhaps I need to try Go out, but I just don't see what the selling point is.

[fauigerzigerk]

People are trying to get as much space as possible between themselves and the Java community's culture of complexity. I don't think it's a technology issue.

[adamc]

"the Java community's culture of complexity" -- great evocative phrase.

[pjmlp]

s/Java/Enterprise/g

[azth]

> but it surprises me so many people jump to Go for performance similar to what you'd get on a modern JVM language

In a word: hype. If Go did not have the Google brand name attached to it, it wouldn't have gone anywhere.

[kkowalczyk]

You're empirically wrong.

I actually did write a fair amount of Go code (my primary languages are C++ and Python).

On real, non-toy programs it is significantly more concise than C++, in the ballpark of Python code.

This isn't visible on code snippets (less than 500 loc) like the toy raytracer, but trust me: you'll see a big difference on 10k loc codebase.

[m0th87]

I've just wrapped up a go program that's not a toy, albeit not as large as 10k - it's a little over 3k. It was not nearly as terse as python, although the performance increases made it well worth it. This is something that surely varies a great deal from one application to another.

[npalli]

Without knowing what your program did, it is hard to see what language features caused the difference. In any case, why was Java not a better option than Golang?

[TylerE]

Go outputs a statically linked binary that just RUNS. Java needs a quite heavyweight runtime to be installed, that imposes quite a bit of startup overhead. That's just one reason - for short runtime CLI-type utilities it's not in the same ballpark.

[npalli]

Ok, so lets go with your use case. You can run basic java ("hello world") under 3MB with a startup time of about 0.1 second. So that is the true overhead if you really care about tight code. The default values are pretty large. Everything else (memory/startup) is added due to external libraries that are needed and additional memory as the program grows.

Given that "kkowalczyk" talked about 10K line programs, what applications are you thinking of that are 10K lines and cannot tolerate a 0.1 second/3 MB overhead. Would you restart java everytime? Note that even a simple helloworld c program has about 0.01second/0.5MB overhead.

[m0th87]

I was going to say there's no way java programs boot in 0.1 seconds, but looked it up to be sure. Here's the results on my mac/i7, defaulted to server mode:

    $ time java HelloWorld
    Hello, world!

    real	0m0.101s

Touche. 0.1 seconds is exactly right, at least on my setup. That said, javac is slow given the program is 5 lines of code:

    $ time javac HelloWorld.java 

    real	0m0.511s
    user	0m0.833s
    sys	0m0.050s

And I'd ventured to guess that there must be something to the JIT being pretty slow for real-world applications, otherwise people wouldn't complain so frequently about it. Maybe aspects of JIT optimizations increase linearly-ish with the amount/complexity of code?

FWIW, we went with go at my work instead of java because our application is memory-intensive, and there's huge gains there in go over java.

[bchjam]

A program that consists solely of println("Hello, World!"); is pretty stateless and trivial, there's not much that a JIT could do with this.

Somewhat anecdotally, I remember hearing Rich Hickey talking about how the JVM JIT loves stateless code. I'm pretty sure the vast majority of Java code in use is deeply stateful. I don't know how much of a difference this actually makes but it seemed like a relevant data point.

[tptacek]

You are off by two orders of magnitude in the C case, at least with my trivial test case of writing hello world, and then a runner program that forks/execs/waitpids 10,000 times.

If you know what crt0.c does, you can see C is also pretty much the asymptote of what you're going to get from program startup, so it's a little silly to make the comparison.

[eliasmacpherson]

Is that with the JVM already running or not?

[pjmlp]

> Java needs a quite heavyweight runtime to be installed, that imposes quite a bit of startup overhead.

One can always use one of the commercial native compilers for Java, any of them can easily produce static binaries with fast startup times.

Don't measure Java the language, by Oracle JVM the implementation.

[myg204]

A lot of the verbosity in Go comes from error handling; the language forces you to deal with errors (I think it's a good thing, some may disagree). Expressiveness is real, 'duck typing' does give it a feel of scripting language like Python, and it is way less verbose than Java (apart from error handling). And to be fair, Go is faster than Python (the numbers tell you that), and (slightly?) more expressive than C --and just in a league of its own for concurrency.

[azth]

> and just in a league of its own for concurrency.

Not really. Other languages are far superior in this regard (see Scala or Rust for instance).

[nly]

I think the reason both versions lack conciseness is because they're faithful translations of one another. I wouldn't call either well structured, but maybe that's because I don't understand the problem domain well enough. T() in the C++ versions especially looks awful.

[corresation]

To concur with what kkowalczyk, there is little expressiveness advantages to be gained for this specific example -- math is math, and outside of compressing it down to a couple of library calls, what could possibly be done better?

"they ended up with a language with the expressiveness of C and the speed of python."

This is just pure troll. Apparently you have a Python variant of this renderer that matches the already impressive Go performance? Please reveal it.