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Should a return statement be inside or outside a lock?
...ideal, but I wouldn't bend the code out of shape just to achieve it... And if the alternative is declaring a local variable (outside the lock), initializing it (inside the lock) and then returning it (outside the lock), then I'd say that a simple "return foo" inside the lock is a lot simpler.
To sh...
Why return NotImplemented instead of raising NotImplementedError
...hould ask someone else to satisfy the operation. In the expression a == b, if a.__eq__(b) returns NotImplemented, then Python tries b.__eq__(a). If b knows enough to return True or False, then the expression can succeed. If it doesn't, then the runtime will fall back to the built-in behavior (which ...
关于php的socket初探 - PHP - 清泛IT论坛,有思想、有深度
...;global $errno, $errstr;
if ($port < 1024) {
die("Port must be a number which bigger than 1024/n");
}
&n...
Extract substring in Bash
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If x is constant, the following parameter expansion performs substring extraction:
b=${a:12:5}
where 12 is the offset (zero-based) and 5 is the length
If the underscores around the digits are the only ones in the input, y...
Vibrate and Sound defaults on notification
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The vibration now has a delay of 1000 ms. If you set the first one to 0, it will go off instantly. It's a { delay, vibrate, sleep, vibrate, sleep } pattern.
– Tom
Apr 30 '15 at 11:22
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Code equivalent to the 'let' keyword in chained LINQ extension method calls
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Woah, I didn't know you could autoencapsulate using the new operator like that.
– David Pfeffer
Sep 22 '10 at 15:31
19
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What's the best way to send a signal to all members of a process group?
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You don't say if the tree you want to kill is a single process group. (This is often the case if the tree is the result of forking from a server start or a shell command line.) You can discover process groups using GNU ps as follows:
p...
What is the difference between 'my' and 'our' in Perl?
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Great question: How does our differ from my and what does our do?
In Summary:
Available since Perl 5, my is a way to declare non-package variables, that are:
private
new
non-global
separate from any package, so that the variable cannot be accessed i...
What's the difference between echo, print, and print_r in PHP?
...ess the same; they are both language constructs that display strings. The differences are subtle: print has a return value of 1 so it can be used in expressions whereas echo has a void return type; echo can take multiple parameters, although such usage is rare; echo is slightly faster than print. (P...
Circle line-segment collision detection algorithm?
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(x - h)2 + (y - k)2 = r2
(h,k) = center of circle.
Note: We've simplified the problem to 2D here, the solution we get applies also in 3D
to get:
Expand
x2 - 2xh + h2 + y2 - 2yk + k2 - r2 = 0
Plug
x = ex + tdx
y = ey + tdy
( ex + tdx )2 - 2( ex + tdx )h + h2 +
( ey + tdy )2 - 2( ey + tdy ...