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WebSocket is protocol, which enables two-way communication between a client and server: The goal WebSocket is to provide a mechanism for browser-based applications that need two-way communication with servers that does not rely on opening multiple HTTP connections. (RFC 6455) WebSocket works ove...

\C (any one character except newline) 'all literal except single quotes'; 'this: '\'' is a single quote' $'only \\ and \' are special; \n = newline etc.' "$variable and other text; \"\\\$\` are special"

Bitwise operations alter binary strings at the bit level. These operations are incredibly basic and are directly supported by the processor. These few operations are necessary in working with device drivers, low-level graphics, cryptography, and network communications. This section provides useful k...

[[ -OP $filename ]] [[ $file1 -OP $file2 ]] [[ -z $string ]] [[ -n $string ]] [[ "$string1" == "$string2" ]] [[ "$string1" == $pattern ]] The [[ … ]] syntax surrounds bash built-in conditional expressions. Note that spaces are required on either side of th...

Maps are data types used for storing unordered key-value pairs, so that looking up the value associated to a given key is very efficient. Keys are unique. The underlying data structure grows as needed to accommodate new elements, so the programmer does not need to worry about memory management. They...

A slice is a data structure that encapsulates an array so that the programmer can add as many elements as needed without having to worry about memory management. Slices can be cut into sub-slices very efficiently, since the resulting slices all point to the same internal array. Go programmers often ...

NSArray *words; // Declaring immutable array NSMutableArray *words; // Declaring mutable array NSArray *words = [NSArray arrayWithObjects: @"one", @"two", nil]; // Array initialization syntax NSArray *words = @[@"list", @"of", @"words", ...

<element lang="language_code">   <!-- Language code has to be in the format [ISO 639-1](https://en.wikipedia.org/wiki/ISO_639-1 ) --> The value of the lang attribute must be a valid BCP 47 language tag or the empty string (if the language is unknown). The BCP 47 ...

SomeClass sc = new SomeClass { Property1 = value1, Property2 = value2, ... }; SomeClass sc = new SomeClass(param1, param2, ...) { Property1 = value1, Property2 = value2, ... } The constructor parentheses can only be omitted if the type being instantiated has a default (parameterless) const...

Recursion is mostly available in Perl-compatible flavors, such as: Perl PCRE Oniguruma Boost

Some times you need to create extended text documentation from you xml comments. Unfortunatly there is no standard way for it. But there are some separate projects that you can use for this case: Sandcastle Docu NDoc DocFX

Build a named capture group (X being the pattern you want to capture): (?'name'X) (?X) (?PX) Reference a named capture group: ${name} \{name} g\{name} Python and Java don't allow multiple groups to use the same name.

This topic outlines how and when the Swift runtime shall allocate memory for application data structures, and when that memory shall be reclaimed. By default, the memory backing class instances is managed through reference counting. The structures are always passed through copying. To opt out of th...

shift shifts the positional parameters to the left so that $2 becomes $1, $3 becomes $2 and so forth. "$@" is an array of all the positional parameters passed to the script/function. "$*" is an string composed of all the positional parameters passed to the script/function. ...

WITH QueryName [(ColumnName, ...)] AS (   SELECT ... ) SELECT ... FROM QueryName ...; WITH RECURSIVE QueryName [(ColumnName, ...)] AS (   SELECT ...   UNION [ALL]   SELECT ... FROM QueryName ... ) SELECT ... FROM QueryName ...; Official documentation: WITH clause A Common ...

A swarm is a number of Docker Engines (or nodes) that deploy services collectively. Swarm is used to distribute processing across many physical, virtual or cloud machines. Initialize a swarm: docker swarm init [OPTIONS] Join a swarm as a node and/or manager: docker swarm join [OPTIONS]...

transition: [transition-property] [transition-duration] [transition-timing-function] [transition-delay]; ParameterDetailstransition-propertyThe specific CSS property whose value change needs to be transitioned (or) all, if all the transitionable properties need to be transitioned.transition-...

Foldable is the class of types t :: * -> * which admit a folding operation. A fold aggregates the elements of a structure in a well-defined order, using a combining function. If t is Foldable it means that for any value t a we know how to access all of the elements of a from "inside&qu...