A basic concept on YAML

Before starting with YAML here is some concept of serialization

SERIALIZATION

It is a process of translating data structure/object in a format for storage purpose. The storage format later can be used to reconstruct into original object. The bits order in serialization can be used to create semantically identical clone. Marshalling is the process of object serialization. Deserialization is extracting a data structure from a series of bytes, opposite of serialization.

Uses of Serialization:

Transferring data through wire
Storing data
Remote procedure calls (ex: SOAP)
Detecting changes in time varying data.

Serialization mainly helps data structure to be architecture-independent format for storing, transferring or other uses among different programming languages. It also helps in byte-ordering, memory layout and provides simple different ways of representing data.

Limitations:

It breaks opacity of the abstract data types by exposing implementation details. Other way, it violates encapsulation.

Formats of serialization:

XML & SGML-------> In the late 1990s XML, and SGML subset, was used to produce a human readable text-based encoding. XML was often used for asynchronous transfer of structured data between client and server in Ajax web applications. XML is an open format.
JSON------> A lighter plain-text alternative to XML based on JavaScript syntax, is also used for client-server communication in web applications.
YAML-----> a strict JSON superset, YAML is an open format. (details are given below)
Property lists -----> p-list for short, doesn't refer to a single serialization format but instead several different variants, some human-readable and one binary. It is used for serialization by NeXTSTEP, GNUstep, macos and IOS frameworks. you can learn more Property lists here. 😀 😁

Supported programming languages:

C/C++-------> Boost framework and MFC framework (microsoft)
CFML-----> WDDX
GO -----> JSON & XML
Haskell -------> type classes.

And many other program languages java, JavaScript, julia, python, Ruby etc.

YEYY!!! you completed the most important part of the topic 🥳🥳.

HERE COMES YAML!!!

YAML

YAML recursive acronym stands for “YAML Ain't Markup Language”. Firstly, it’s not markup language. It is a human friendly data serialization language and most importantly works perfectly with other programming languages. It is often used to write configuration files.

Features of YAML:

YAML is a data-oriented language that has features derived from Perl, C, HTML, and other languages.
YAML is a superset of JSON that comes with multiple built-in advantages such as including comments, self-referencing, and support for complex datatypes.
YAML data is portable between programming languages
Supports one-direction processing
Matches native data structures of agile methodology
Supports non-hierarchical data models
YAML specification identifies an instance document as a "Presentation" or "character stream.
Purely a data-representation language and thus has no executable commands

Multiple software packages have implemented YAML to create powerful configuration management tools such as Red Hat’s Ansible

YAML Syntax:

yaml datatypes: Values in YAML's key-value pairs are scalar. They act like the scalar types in languages like Perl, Javascript, and Python. The following data types are supported by YAML:

Types Description String Strings are enclosed with or without double or single quotes number It can be integers or floating values Boolean Accepts true or false sequence Supports array or list Set Set stores the elements with unordered without duplicates Map maps stores key with value as like hash map binary support binary data of octal strings - images,files timestamp Supports date, datetime

Rules for Creating YAML file:

basic rules:

YAML is case sensitive
The files should have .yaml as the extension
YAML does not allow the use of tabs while creating YAML files; spaces are allowed instead

How YAML Works:

Scalars, or variables, are defined using a colon and a space.

integer: 25 
string: "25" 
float: 25.0 
boolean: Yes

numeric types

```

foo: 12345 bar: 0x12d4 plop: 023332


strings are Unicode

foo: "this is not a normal string\n" bar: this is not a normal string\n


nulls with a tilde or the unquoted null string literal

foo: ~ bar: null


boolean values

foo: True bar: False light: On TV: Off


arrays

items: [ 1, 2, 3, 4, 5 ] names: [ "one", "two", "three", "four" ]



dictionaries

foo: { thing1: huey, thing2: louie, thing3: dewey }



2. Associative arrays and lists can be defined using a conventional block format or an inline format that is similar to JSON.

--- # Shopping List in Block Format

milk - eggs – juice

--- # Shopping List in Inline Format [milk, eggs, juice]



3. Strings do not require quotation mark. Strings can be denoted with a | character, which preserves newlines, or a > character, which folds newlines.

data: | Each of these Newlines Will be broken up

data: > This text is wrapped and will be formed into a single paragraph

4. block format uses hyphen (-) and space to begin a new item in a specified list

--- # Favorite movies

Casablanca
North by Northwest
The Man Who Wasn't There


5. Comments begin with a pound sign

___
 This is a full line comment
foo: bar # this is a comment, too

Synopsis of YAML Basic Elements:
-	The synopsis of YAML basic elements is given here: Comments in YAML begins with the (#) character.
-	Comments must be separated from other tokens by whitespaces.
-	Indentation of whitespace is used to denote structure.
-	Tabs are not included as indentation for YAML files.
-	List members are denoted by a leading hyphen (-).
-	List members are enclosed in square brackets and separated by commas.
-	Associative arrays are represented using colon ( : ) in the format of key value pair. They are enclosed in curly braces {}.
-	Multiple documents with single streams are separated with 3 hyphens (---).
-	Repeated nodes in each file are initially denoted by an ampersand (&) and by an asterisk (*) mark later.
-	YAML always requires colons and commas used as list separators followed by space with scalar values.
-	Nodes should be labelled with an exclamation mark (!) or double exclamation mark (!!), followed by string which can be expanded into an URI or URL.

Advanced component:

 YAML has the strip chomp and preserve chomp operators. To save the last character, add a plus to the fold or block operators.
 

bar: >+
  this is not a normal string it
  spans more than
  one line
  see?
 

if the value ends with whitespace, like a newline, YAML will preserve it. To strip the character, use the strip operator.

liza314 / YAML