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[MagmaMcFry]

There is in fact a better way:

Code: (Preparation) [Select]

totalElements = 0
for each list in listOfLists
    totalElements += list.length


Code: (Generation) [Select]

i = rand.nextInt(totalElements)
for each list in listOfLists
    if i < list.length
        return list[i]
    else
        i -= list.length


[miauw62]

There is in fact a better way:

Code: (Preparation) [Select]

totalElements = 0
for each list in listOfLists
    totalElements += list.length


Code: (Generation) [Select]

i = rand.nextInt(totalElements)
for each list in listOfLists
    if i < list.length
        return list[i]
    else
        i -= list.length


That looks like my suggestion, actually

[Sinlessmoon]

Ptw because I'm about to seriously delve into programming.

Gotta get back to my precious C#.

[dreadmullet]

I've recently been playing around with creating and joining threads in static initialization/deinitialization (C++). That is, pre-main and post-main. Short version: don't do it. Even if it works in one case, it will probably fail randomly somewhere down the line, and it's probably not portable.

Case in point: this short program works fine on gcc, but with msvc it hangs on shutdown. After main ends, the thread stops and is joined, but it hangs on the join() call.

Code: (C++) [Select]

#include <chrono>
#include <thread>

bool isLooping = true;

struct TestClass{
std::thread thread;
~TestClass(){
isLooping = false;
this->thread.join();
}
};

TestClass testClass;

void AsyncLoop(){
while(isLooping){
std::this_thread::sleep_for(std::chrono::milliseconds(100));
}
}

int main(){
testClass.thread = std::thread(&AsyncLoop);

return 0;
}

[SolarShado]

I've recently been playing around with creating and joining threads in static initialization/deinitialization (C++). That is, pre-main and post-main. Short version: don't do it. Even if it works in one case, it will probably fail randomly somewhere down the line, and it's probably not portable.

Yeah this was my gut reaction:

don't do it.

Why would do that anyway? I'm genuinely curious as to what legitimate use it could have.

Pardon my C++ ignorance, but isn't pretty much anything "pre-main/post-main" non-portable?

[MorleyDev]

You can do pre-main portably I believe, but you have to have a really good grip on the few guarantees you have over how initialisation happens which you only really get with static variables inside functions. And deinitialisation is much more of a free-for-all.

The only real usage of it I've found that doesn't fall into the category of "don't do it" is for registering test fixtures in a testing library, so that the underlying code adds each fixture to a global collection of fixtures before you hit the main function.

[dreadmullet]

Why would do that anyway? I'm genuinely curious as to what legitimate use it could have.

I wanted to create a thread on program startup and have it end on program shutdown, without having to call Init and DeInit functions or something. It would be really nice if there were an easy, clean way; does anyone have any suggestions?

[MagmaMcFry]

Use init and destroy methods. This may look like a disadvantage because you have to put two function calls in your main method, but it has the advantage of being well-defined, and you can run some quick tests before calling init() to see if it's actually worth allocating those resources or if there's something wrong (e.g. user error).

[dreadmullet]

It was part of a small logging library, but, yes, that's the solution that I went with in the end. Better yet, I wrapped Init and Deinit in the constructor and destructor of a class. RAII, yo.

[Dutchling]

So I'm trying to use a Python Perlin Noise thing I found a Github. Installations instruction are as follows:

Installation uses the standard Python distutils regime:

python setup.py install

This will compile and install the noise package into your Python site
packages.

I have absolutely no idea what this means. Halp?
(I use Windows by the way. This would be kinda trivial with Ubuntu)

[MagmaMcFry]

I have absolutely no idea what this means. Halp?

Download the thing, open a shell, navigate to the folder containing setup.py, then run the command "python setup.py install". At least that's what it says there.

[Dutchling]

So there's no proper way to install it :x?

[MagmaMcFry]

Well, that's what the instructions say, and it looks like the setup.py actually internally uses the proper way to install it.

[Dutchling]

I opened command prompt and navigated to my download folder.

'python' is not recognized as an internal or external command, operable program or batch file.

This is kinda the reason why I always try to avoid github as much as possible >.<

[alexandertnt]

Where did you install Python and which version is it?

You may have to type something like "drive:\path\to\python.exe setup.py install" e.g. "C:\Python26\python.exe setup.py install"