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Tips for debugging .htaccess rewrite rules
...ST['ntests'] : 1;
$a_test = isset($_POST['test']) ? $_POST['test'] : array();
$res = array(); $maxM=-1;
foreach($a_test as $t ){
$rtn = @preg_match('#'.$a_pattern.'#',$t,$m);
if($rtn == 1){
$maxM=max($maxM,count($m));
$res[]=array_merge( ar...
Elegant way to invert a map in Scala
...bf()) += k))
}
}.mapValues(_.result())
}
usage:
Map(2 -> Array('g','h'), 5 -> Array('g','y')).invert
//res0: Map(g -> Array(2, 5), h -> Array(2), y -> Array(5))
Map('q' -> 1.1F, 'b' -> 2.1F, 'c' -> 1.1F, 'g' -> 3F).invert
//res1: Map(1.1 -> Set(q, c), 2....
Why is the minimalist, example Haskell quicksort not a “true” quicksort?
...ort C code into Haskell. Brace yourself.
import Control.Monad
import Data.Array.IO
import Data.IORef
qsort :: IOUArray Int Int -> Int -> Int -> IO ()
qsort a lo hi = do
(h,l,p,t) <- liftM4 (,,,) z z z z
when (lo < hi) $ do
l .= lo
h .= hi
p .=. (a!hi)
doWhile (...
Double not (!!) operator in PHP
...ns that for any true value (numbers other than zero, non-empty strings and arrays, etc.) you will get the boolean value TRUE, and for any false value (0, 0.0, NULL, empty strings or empty arrays) you will get the boolean value FALSE.
It is functionally equivalent to a cast to boolean:
return (bool...
What is a “context bound” in Scala?
...s article? It covers the new context bound feature, within the context of array improvements.
Generally, a type parameter with a context bound is of the form [T: Bound]; it is expanded to plain type parameter T together with an implicit parameter of type Bound[T].
Consider the method tabulate...
Java Reflection Performance
...rom S.O. as bad / misleading information. Cache the created objects in an array in both cases to prevent the optimizer from optimizing it out. (It can't do this in the reflective situation because it can't prove that the constructor doesn't have side-effects)
– Bill K
...
:: (double colon) operator in Java 8
...1 = System::exit; // void exit(int status)
Consumer<String[]> b2 = Arrays::sort; // void sort(Object[] a)
Consumer<String> b3 = MyProgram::main; // void main(String... args)
class Hey {
public double getRandom() {
return Math.random();
}
}
Callable<Double> call...
Does static constexpr variable inside a function make sense?
If I have a variable inside a function (say, a large array), does it make sense to declare it both static and constexpr ? constexpr guarantees that the array is created at compile time, so would the static be useless?
...
PHP Foreach Pass by Reference: Last Element Duplicating? (Bug?)
...f the loop, we'll echo the value of $item as well as recursively print the array $arr.
When the first loop is run through, we see this output:
foo
Array ( [0] => foo [1] => bar [2] => baz )
bar
Array ( [0] => foo [1] => bar [2] => baz )
baz
Array ( [0] => foo [1] => bar [2]...
How can I convert an RGB image into grayscale in Python?
...o use scikit-image, which provides some functions to convert an image in ndarray, like rgb2gray.
from skimage import color
from skimage import io
img = color.rgb2gray(io.imread('image.png'))
Notes: The weights used in this conversion are calibrated for contemporary CRT phosphors: Y = 0.2125 R +...