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How can we match a^n b^n with Java regex?
...tion (?=…).
Here is our pattern with a simple test harness:
function testAll($r, $tests) {
foreach ($tests as $test) {
$isMatch = preg_match($r, $test, $groups);
$groupsJoined = join('|', $groups);
print("$test $isMatch $groupsJoined\n");
}
}
$tests = array('aaa', 'aaab',...
pythonic way to do something N times without an index variable?
...ghtly faster approach than looping on xrange(N) is:
import itertools
for _ in itertools.repeat(None, N):
do_something()
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Real differences between “java -server” and “java -client”?
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This is really linked to HotSpot and the default option values (Java HotSpot VM Options) which differ between client and server configuration.
From Chapter 2 of the whitepaper (The Java HotSpot Performance Engine Architecture):
The JD...
Is there a way to iterate over a range of integers?
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I don't think most people would call this three-expression version more simple than what @Vishnu wrote. Only perhaps after years and years of C or Java indoctrination ;-)
– Thomas Ahle
Jun 28 '14 at 21:06
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Symfony 2: How do I check if a user is not logged in inside a template?
...any user is logged in.
{% if app.user %}
# user is logged in (any and all users, regardless of ROLE_*)
{% elseif not app.user %}
# user is not logged in (note the `not` in the `elseif` statement)
{% endif %}
Checking authentication status
You can use the is_granted() method to check fo...
How to open link in new tab on html?
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The special targets all start with an underscore. blank would be the name of a frame or window. It may seem to work, because a new window or tab will probably be opened when none exists with the name 'blank', but a second click on the link shoul...
Installation Issue with matplotlib Python [duplicate]
I have issue after installing the matplotlib package unable to import matplotlib.pyplot as plt . Any suggestion will be greatly appreciate.
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`staticmethod` and `abc.abstractmethod`: Will it blend?
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class abstractstatic(staticmethod):
__slots__ = ()
def __init__(self, function):
super(abstractstatic, self).__init__(function)
function.__isabstractmethod__ = True
__isabstractmethod__ = True
class A(object):
__metaclass__ = abc.AB...
Function to calculate distance between two coordinates
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What you're using is called the haversine formula, which calculates the distance between two points on a sphere as the crow flies. The Google Maps link you provided shows the distance as 2.2 km because it's not a straight line.
Wolphram Alpha is...
PHP Session Security
...or maintaining responsible session security with PHP? There's information all over the web and it's about time it all landed in one place!
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