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...
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...
C-h k runs the function describe-key, which looks up the function mapped to the key strokes provided, and presents a description of the function which will be run when these keys are pressed.
C-h c runs the function describe-key-briefly, which only displays the function name mapped to given key seq...
C-h f runs the function describe-function, which displays information on the usage and purpose of a given function. This is especially useful for functions that do not have a mapped key binding that can be used for documentation lookup via C-h k.
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...
The Data.Vector module provided by the vector is a high performance library for working with arrays.
Once you've imported Data.Vector, it's easy to start using a Vector:
Prelude> import Data.Vector
Prelude Data.Vector> let a = fromList [2,3,4]
Prelude Data.Vector> a
fromList [2,3,4]...
Vectors can be map'd and fold'd,filter'd andzip`'d:
Prelude Data.Vector> Data.Vector.map (^2) y
fromList [0,1,4,9,16,25,36,49,64,81,100,121] :: Data.Vector.Vector
Reduce to a single value:
Prelude Data.Vector> Data.Vector.foldl (+) 0 y
66
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...
These rules apply only if you use manual reference counting!
You own any object you create
By calling a method whose name begins with alloc, new, copy or mutableCopy.
For example:
NSObject *object1 = [[NSObject alloc] init];
NSObject *object2 = [NSObject new];
NSObject *object3 = [object2 ...
After you have opened a split window in vim (as demonstrated by many examples under this tag) then you will likely want to control windows quickly. Here is how to control split windows using keyboard shortcuts.
Move to split Above/Below:
Ctrl + w and k
Ctrl + w and j
Move to split Left/Right...
The Window Object contains the following properties.
PropertyDescriptionwindow.closedWhether the window has been closedwindow.lengthNumber of <iframe> elements in windowwindow.nameGets or sets the name of the windowwindow.innerHeightHeight of windowwindow.innerWidthWidth of windowwindow.scree...
Many unbound generic parameters, like those used in a static method, cannot be recovered at runtime (see Other Threads on Erasure). However there is a common strategy employed for accessing the type satisfying a generic parameter on a class at runtime. This allows for generic code that depends on ac...
# Deny access to a directory from the IP 255.0.0.0
<Directory /path/to/directory>
order allow,deny
deny from 255.0.0.0
allow from all
</Directory>
# Deny access to a file from the IP 255.0.0.0
<FilesMatch "^\.ht">
order allow,deny
deny fro...
python-social-auth is a framework that simplifies the social authentication and authorization mechanism. It contains many social backends (Facebook, Twitter, Github, LinkedIn, etc.)
INSTALL
First we need to install the python-social-auth package with
pip install python-social-auth
or download ...
