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How is this fibonacci-function memoized?
...nacci definition, fib n = fib (n-1) + fib (n-2), the function itself gets called, twice from the top, causing the exponential explosion. But with that trick, we set out a list for the interim results, and go "through the list":
fib n = (xs!!(n-1)) + (xs!!(n-2)) where xs = 0:1:map fib [2..]
The tr...
Is it possible to install iOS 6 SDK on Xcode 5?
Xcode 5 has a preferences pane that allow one to download iPhone 6.1 simulator, however I can't find a place where it allows downloading of iOS 6 SDK, thus it is not possible to set the active SDK to iOS 6 when developing with Xcode 5. Is there a workaround that would allow Xcode 5 to install iOS 6 ...
What's a good rate limiting algorithm?
...sages
per = 8.0; // unit: seconds
allowance = rate; // unit: messages
last_check = now(); // floating-point, e.g. usec accuracy. Unit: seconds
when (message_received):
current = now();
time_passed = current - last_check;
last_check = current;
allowance += time_passed * (rate / per);
if (...
Get Unix Epoch Time in Swift
...alSince1970)
let preciseMilliseconds = Int(Date().timeIntervalSince1970 * 1_000)
let preciseMicroseconds = Int(Date().timeIntervalSince1970 * 1_000_000) // most likely precise
Unfortunately, however, in the year 2038, 32-bit numbers won't be usable for the Unix timestamp and they'll have to be 64-...
Is it possible to figure out the parameter type and return type of a lambda?
...Andry that's a fundamental problem with function objects that have (potentially) multiple overloads of operator() not with this implementation. auto is not a type, so it can't ever be the answer to traits::template arg<0>::type
– Caleth
Jan 16 '18 at 12:1...
Objective-C: Property / instance variable in category
...e, it wouldn't work.
Fortunately, the Objective-C runtime has this thing called Associated Objects that can do exactly what you're wanting:
#import <objc/runtime.h>
static void *MyClassResultKey;
@implementation MyClass
- (NSString *)test {
NSString *result = objc_getAssociatedObject(sel...
JavaFX and OpenJDK
...s a modular library accessed from an existing JDK (such as an Open JDK installation).
The open source code repository for JavaFX is at https://github.com/openjdk/jfx.
At the source location linked, you can find license files for open JavaFX (currently this license matches the license for OpenJDK...
https URL with token parameter : how secure is it?
...ased on their private information (given through a form). We would like to allow them to get back on their simulation results later, but without forcing them to create a login/password account.
...
iOS app error - Can't add self as subview
...ControllerDelegate protocol.
This includes the following method, which is called after the animation is complete:
navigationController:didShowViewController:animated:
Basically you want to move some code as needed into this method to ensure that no other actions that could cause a change to the N...
Can't start Eclipse - Java was started but returned exit code=13
...ng Eclipse. I ran into this problem when trying to run Eclipse, having installed version 4.2 only minutes ago.
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