Find meaningful names for computation units.
Use for comprehensions or map to combine computations together.
Let's say you have something like this:
if (userAuthorized.nonEmtpy) {
makeRequest().map {
case Success(respone) =>
someProcessing(..)
if (resendToUser) {
...
By default:
Use val, not var, wherever possible. This allows you to take seamless advantage of a number of functional utilities, including work distribution.
Use recursion and comprehensionss, not loops.
Use immutable collections. This is a corrolary to using val whenever possible.
Focus on da...
This example shows a white Snackbar with custom Undo icon.
Snackbar customBar = Snackbar.make(view , "Text to be displayed", Snackbar.LENGTH_LONG);
customBar.setAction("UNDO", new View.OnClickListener() {
@Override
public void onClick(View view) {
//Put the logic...
The blob.slice() method is used to create a new Blob object containing the data in the specified range of bytes of the source Blob. This method is usable with File instances too, since File extends Blob.
Here we slice a file in a specific amount of blobs. This is useful especially in cases where yo...
Say we have Products and Categorys in a many-to-many relationship:
public class Product
{
public Product()
{
Categories = new HashSet<Category>();
}
public int ProductId { get; set; }
public string ProductName { get; set; }
public virtual ICollection<...
There is no format specifier to print boolean type using NSLog. One way to print boolean value is to convert it to a string.
BOOL boolValue = YES;
NSLog(@"Bool value %@", boolValue ? @"YES" : @"NO");
Output:
2016-07-30 22:53:18.269 Test[4445:64129] Bool value YES
...
The Fibonacci numbers are defined inductively as
F0 = 0
F1 = 1
Fn+2 = Fn + Fn+1
The sum of the first n+1 Fibonacci numbers is given by
F0 + F1 + F2 + ... + Fn = Fn+2 - 1.
This summation arises, among other places, in the analysis of Fibonacci heaps, where it's used to provide a lower b...
You can animate complex changes to your collection view using the performBatchUpdates method. Inside the update block, you can specify several modifications to have them animate all at once.
collecitonView.performBatchUpdates({
// Perform updates
}, nil)
Inside the update block, you can pe...
Before starting with the example I'd recommend to create a Singleton with a delegate class member so you could achieve a use case of uploading a file in the background and let the user keep using your app while the files are being uploaded even when the app is the background.
Let's start, first, we...
If all you need is to wrap the value into a promise, you don't need to use the long syntax like here:
//OVERLY VERBOSE
var defer;
defer = $q.defer();
defer.resolve(['one', 'two']);
return defer.promise;
In this case you can just write:
//BETTER
return $q.when(['one', 'two']);
$q.when ...
C-h t runs the function help-with-tutorial, which opens a buffer containing a tutorial on the basic editing functionality of emacs, including moving around in text, and working with files, buffers, and windows.
Pressing C-h a will run the emacs function apropos-command which makes emacs prompt for words (or a regexp) to search for. It will then show a buffer containing a list of names and descriptions related to that topic, including key bindings for each of the functions available via keystrokes.
Pressin...
Another powerful & mature concurrency tool in Haskell is Software Transactional Memory, which allows for multiple threads to write to a single variable of type TVar a in an atomic manner.
TVar a is the main type associated with the STM monad and stands for transactional variable. They're used m...
Zip two arrays into an array of pairs:
Prelude Data.Vector> Data.Vector.zip y y
fromList [(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9),(10,10),(11,11)] :: Data.Vector.Vector
By default Code First includes in model
Types defined as a DbSet property in context class.
Reference types included in entity types even if they are defined in
different assembly.
Derived classes even if only the base class is defined as DbSet
property
Here is an example, that we are only...
select returns a new hash with key-value pairs for which the block evaluates to true.
{ :a => 1, :b => 2, :c => 3 }.select { |k, v| k != :a && v.even? } # => { :b => 2 }
When you will not need the key or value in a filter block, the convention is to use an _ in that place:...
Intersection of Hashes
To get the intersection of two hashes, return the shared keys the values of which are equal:
hash1 = { :a => 1, :b => 2 }
hash2 = { :b => 2, :c => 3 }
hash1.select { |k, v| (hash2.include?(k) && hash2[k] == v) } # => { :b => 2 }
Union (...
Vim knows The Answer:
:help 42
Vim will open the usr_42.txt document from the manual and show the following text:
What is the meaning of life, the universe and everything? 42
Douglas Adams, the only person who knew what this question really was about is
now dead, unfortunately. So now you m...
Selectors are used as method identifiers in Objective-C.
In the example below, there are two selectors. new and setName:
Person* customer = [Person new];
[customer setName:@"John Doe"];
Each pair of brackets corresponds to a message send. On the first line we send a message containin...
