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Is it better to reuse a StringBuilder in a loop?
...sertion pointer back to zero (via .setLength(0)). Those answers suggesting allocating a brand new StringBuilder per loop do not seem to realise that .toString creates yet another copy, so each iteration requires two buffers as opposed to the .setLength(0) method which only requires one new buffer p...
Python hashable dicts
...using itervalues will access the values directly and avoid the many memory allocator calls using by items to form new many key/value tuples in memory every time you do a lookup.
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When to use Task.Delay, when to use Thread.Sleep?
...ch. If you're using a thread pool this could also cause a new thread to be allocated. Both operations are quite heavy whereas the cooperative multi-tasking provided by Task.Delay etc is designed to avoid all of that overhead, maximize throughput, allow cancellation, and provide cleaner code.
...
How to create custom easing function with Core Animation?
...s with a nice sample code.
- (void)viewDidLoad {
UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 50.0, 50.0)];
v.backgroundColor = [UIColor redColor];
CGFloat y = self.view.bounds.size.height;
v.center = CGPointMake(self.view.bounds.size.width/2.0, 50.0/2.0);
[se...
What is the best way to concatenate two vectors?
...
AB.reserve( A.size() + B.size() ); // preallocate memory
AB.insert( AB.end(), A.begin(), A.end() );
AB.insert( AB.end(), B.begin(), B.end() );
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How do I convert struct System.Byte byte[] to a System.IO.Stream object in C#?
...
There's extra space allocated in the MemoryStream buffer by default (just like with e.g. a list). This can be dealt with easily by using the overload that allows you to set capacity, but is only really useful if you don't expect to write any dat...
How do I call Objective-C code from Swift?
...documentation, this Objective-C:
UITableView *myTableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStyleGrouped];
turns into this Swift code:
let myTableView: UITableView = UITableView(frame: CGRectZero, style: .Grouped)
Xcode also does this translation on the fly — y...
Android. Fragment getActivity() sometimes returns null
...eFragment() {
// Implement the Parent.
super();
// Allocate the ActivityBuffer.
this.mActivityBuffer = new ActivityBuffer();
}
@Override
public final void onAttach(final Context pContext) {
// Handle as usual.
super.onAttach(pContext);
...
How can I shuffle the lines of a text file on the Unix command line or in a shell script?
...ort -R (not a true shuffle if there are duplicate input lines)
10.661s - allocating more memory doesn't seem to make a difference
Scala
24.229s
bash loops + sort
32.593s
Conclusions:
Use shuf, if you can - it's the fastest by far.
Ruby does well, followed by Perl.
Python is noticeably s...
In what order are Panels the most efficient in terms of render time and performance?
....
The child does not have to (and frequently does not) fill the entire
allocated space. Control is then returned to the parent Panel and the
layout process is complete.
From Measuring and Arranging Children
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