Tutorial by Examples: ces

Problem ConcurrentDictionary shines when it comes to instantly returning of existing keys from cache, mostly lock free, and contending on a granular level. But what if the object creation is really expensive, outweighing the cost of context switching, and some cache misses occur? If the same key ...

Magento is a very popular eCommerce application. It offers a great deal of customization and abilities from initial install. Here are a few suggestions for optimizing a Magento installation. Enabling Output Compression In your .htaccess file for Magento you will find a section of text starting wit...

Two-element tuples (,) is an example of a type that has a Bifunctor instance. instance Bifunctor (,) where bimap f g (x, y) = (f x, g y) bimap takes a pair of functions and applies them to the tuple's respective components. bimap (+ 2) (++ "nie") (3, "john") --> (5,...

To declare a single namespace with hierarchy use following example: namespace MyProject\Sub\Level; const CONNECT_OK = 1; class Connection { /* ... */ } function connect() { /* ... */ } The above example creates: constant MyProject\Sub\Level\CONNECT_OK class MyProject\Sub\Level\Connection...

File descriptors and FILE objects are per-process resources that cannot themselves be exchanged between processes via ordinary I/O. Therefore, in order for two distinct processes to communicate via an anonymous pipe, one or both participating processes must inherit an open pipe end from the process...

Connecting two child processes via a pipe is performed by connecting each of two children to the parent via different ends of the same pipe. Usually, the parent will not be party to the conversation between the children, so it closes its copies of both pipe ends. int demo() { int pipefds[2]; ...

An example of defining a hash table and accessing a value by the key $hashTable = @{ Key1 = 'Value1' Key2 = 'Value2' } $hashTable.Key1 #output Value1 An example of accessing a key with invalid characters for a property name: $hashTable = @{ 'Key 1' = 'Value3' Key2 = 'Val...

Resource loading in Java comprises the following steps: Finding the Class or ClassLoader that will find the resource. Finding the resource. Obtaining the byte stream for the resource. Reading and processing the byte stream. Closing the byte stream. The last three steps are typically accomp...

The data in the pair can be accessed with utility functions. To access the car, we have to use the car function. (car (cons a b)) > a Also we can verify the following equality: (eq? a (car (cons a b))) > #t

To access the cdr, we have to use the cdr function. (cdr (cons a b)) b Also we can verify the following equality: (eq? b (cdr (cons a b))) #t

Maybe Maybe is an applicative functor containing a possibly-absent value. instance Applicative Maybe where pure = Just Just f <*> Just x = Just $ f x _ <*> _ = Nothing pure lifts the given value into Maybe by applying Just to it. The (<*>) function applies...

When you develop a C++ program, the next step is to compile the program before running it. The compilation is the process which converts the program written in human readable language like C, C++ etc into a machine code, directly understood by the Central Processing Unit. For example, if you have a...

Slices are views into a list of objects, and have type [T], indicating a slice of objects with type T. A slice is an unsized type, and therefore can only be used behind a pointer. (String world analogy: str, called string slice, is also unsized.) Arrays get coerced into slices, and vectors can be...

iOS 10 Now Requires User Permission to Access Media Library, Photos, Camera and other Hardware like these. The solution for this is to add their keys into info.plist with description for user that how we are using their data , iOS already required permissions to access microphone, camera, and m...

String and character literals provide an escape mechanism that allows express character codes that would otherwise not be allowed in the literal. An escape sequence consists of a backslash character (\) followed by one ore more other characters. The same sequences are valid in both character an st...

The reference to the outer class uses the class name and this public class OuterClass { public class InnerClass { public void method() { System.out.println("I can access my enclosing class: " + OuterClass.this); } } } You can access fields and ...

You can delete trailing spaces with the following command. :%s/\s\+$//e This command is explained as follows: enter Command mode with : do this to the entire file with % (default would be for the current line) substitute action s / start of the search pattern \s whitespace character \+ e...

You can convert tabs to spaces by doing the following: First check that expandtab is switched off :set noexpandtab Then :retab! which replaces spaces of a certain length with tabs If you enable expandtab again :set expandtab then and run the :retab! command then all the tabs becomes spaces...

This: class Foo extends Dynamic { // Expressions are only rewritten to use Dynamic if they are not already valid // Therefore foo.realField will not use select/updateDynamic var realField: Int = 5 // Called for expressions of the type foo.field def selectDynamic(fieldName: String) = ...

Slightly counterintuitively (but also the only sane way to make it work), this: val dyn: Dynamic = ??? dyn.x(y) = z is equivalent to: dyn.selectDynamic("x").update(y, z) while dyn.x(y) is still dyn.applyDynamic("x")(y) It is important to be aware of this, or else...