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How do I avoid capturing self in blocks when implementing an API?
...ied inside the block (we're not doing that) but also they are not automatically retained when the block is retained (unless you are using ARC). If you do this, you must be sure that nothing else is going to try to execute the block after the MyDataProcessor instance is released. (Given the structure...
What happens with constraints when a view is removed
...hen I do something like this, I save the constraints like this for a view called view1:
self.portraitConstraints = [NSMutableArray new];
for (NSLayoutConstraint *con in self.view.constraints) {
if (con.firstItem == self.view1 || con.secondItem == self.view1) {
[self.portraitConstraints a...
Set UILabel line spacing
...
Edit: Evidently NSAttributedString will do it, on iOS 6 and later. Instead of using an NSString to set the label's text, create an NSAttributedString, set attributes on it, then set it as the .attributedText on the label. The code you want will be something like this:
NSMuta...
Why prefer two's complement over sign-and-magnitude for signed numbers?
...o add them.
Two's complement addition is very simple. You add numbers normally and any carry bit at the end is discarded. So they're added as follows:
0010
+ 1111
=10001
= 0001 (discard the carry)
0001 is 1, which is the expected result of "2+(-1)".
But in your "intuitive" method, adding is m...
Define a lambda expression that raises an Exception
...ur goal is to avoid a def, this obviously doesn't cut it. It does, however allow you to conditionally raise exceptions, e.g.:
y = lambda x: 2*x if x < 10 else raise_(Exception('foobar'))
Alternatively you can raise an exception without defining a named function. All you need is a strong stom...
Elasticsearch query to return all records
I have a small database in Elasticsearch and for testing purposes would like to pull all records back. I am attempting to use a URL of the form...
...
Dynamically set local variable [duplicate]
How do you dynamically set local variable in Python (where the variable name is dynamic)?
7 Answers
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How to implement __iter__(self) for a container object (Python)
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I normally would use a generator function. Each time you use a yield statement, it will add an item to the sequence.
The following will create an iterator that yields five, and then every item in some_list.
def __iter__(self):
...
How exactly does __attribute__((constructor)) work?
...
It runs when a shared library is loaded, typically during program startup.
That's how all GCC attributes are; presumably to distinguish them from function calls.
GCC-specific syntax.
Yes, this works in C and C++.
No, the function does not need to be static.
The destructo...
Sending a notification from a service in Android
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Both Activity and Service actually extend Context so you can simply use this as your Context within your Service.
NotificationManager notificationManager =
(NotificationManager) getSystemService(Service.NOTIFICATION_SERVICE);
Notification notificatio...