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How to wait for several Futures?
Suppose I have several futures and need to wait until either any of them fails or all of them succeed.
8 Answers
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Is there a way to measure how sorted a list is?
...Formally, let A(1), A(2), ..., A(n) be a sequence of n numbers.If i < j and A(i) > A(j), then the pair (i,j) is called an inversion of A.
The inversion number of a sequence is one common measure of its sortedness.Formally, the inversion number is defined to be the number of inversions, that is...
What are 'closures' in .NET?
...
The general feature of closures is implemented in C# by anonymous methods and lambda expressions.
Here's an example using an anonymous method:
using System;
class Test
{
static void Main()
{
Action action = CreateAction();
action();
action();
}
static Act...
PHP: How to send HTTP response code?
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I just found this question and thought it needs a more comprehensive answer:
As of PHP 5.4 there are three methods to accomplish this:
Assembling the response code on your own (PHP >= 4.0)
The header() function has a special use-case that detects...
Checking in packages from NuGet into version control?
...o enable your projects to support pack restore you need to run another command:
Enable-PackageRestore
Now you are ready to commit your code base without the packages folder. The previous command changed your project files so that if packages are missing they get automatically downloaded and added...
Why do you need ./ (dot-slash) before executable or script name to run it in bash?
...Unix, usually, the current directory is not in $PATH.
When you type a command the shell looks up a list of directories, as specified by the PATH variable. The current directory is not in that list.
The reason for not having the current directory on that list is security.
Let's say you're root and...
Hadoop “Unable to load native-hadoop library for your platform” warning
...p.so.1.0.0 was actually compiled on 32 bit.
Anyway, it's just a warning, and won't impact Hadoop's functionalities.
Here is the way if you do want to eliminate this warning, download the source code of Hadoop and recompile libhadoop.so.1.0.0 on 64bit system, then replace the 32bit one.
Steps o...
Which maven dependencies to include for spring 3.0?
I am trying to do my first project with Spring 3.0 (and maven). I have been using Spring 2.5 (and primer versions) in quite some projects. Nevertheless I am kinda confused, what modules I have to define as dependencies in my pom.xml. I just want to use the core container functions (beans, core, cont...
Truncating floats in Python
...
First, the function, for those who just want some copy-and-paste code:
def truncate(f, n):
'''Truncates/pads a float f to n decimal places without rounding'''
s = '{}'.format(f)
if 'e' in s or 'E' in s:
return '{0:.{1}f}'.format(f, n)
i, p, d = s.partitio...
How to check if PHP array is associative or sequential?
...kurO.
For the second question (checking whether the array is zero-indexed and sequential), you can use the following function:
function isAssoc(array $arr)
{
if (array() === $arr) return false;
return array_keys($arr) !== range(0, count($arr) - 1);
}
var_dump(isAssoc(['a', 'b', 'c'])); //...