YAML

Overview

YAML, an acronym for "YAML Ain't Markup Language", is a human-readable data serialization language. It is commonly used for configuration files and in applications where data is being stored or transmitted. YAML targets many of the same communications applications as Extensible Markup Language but has a minimal syntax which intentionally differs from SGML.

History

YAML was first proposed by Clark Evans in 2001, who designed it together with Ingy döt Net and Oren Ben-Kiki. The language's name, "YAML Ain't Markup Language", is a recursive acronym, which was chosen to distinguish its purpose as data-oriented, rather than document markup.

Syntax

YAML uses both Python-style indentation to indicate nesting, and a more compact format that uses [...] for lists and {...} for maps making it similar to JavaScript Object Notation. Blocks of text may be treated as scalars.

Basic Structures

YAML has three main types of structures: scalars (strings and numbers), sequences (arrays/lists), and mappings (hashes/dictionaries).

Scalars are simple, single-part values. They can be written in plain style (unquoted) or quoted using double- or single-quote characters.
Sequences use a dash followed by a space: "- ".
Mappings use a colon followed by a space: ": ".

Data Types

YAML has explicit notation for both ordered maps and sets. It also has support for several common data types such as timestamps, booleans, floats, integers, and nulls.

Usage

YAML is often used in configuration files, data exchange between languages with different data structures, and for data serialization. It is also used in many programming languages for data serialization.

Advantages and Disadvantages

YAML has several advantages over other data serialization formats. It is human-readable, supports complex data structures, can handle large amounts of data, and has wide language support. However, it also has some disadvantages such as being verbose and having potential security vulnerabilities.

Comparison with Other Languages

YAML is often compared with other data serialization languages like JSON and XML. Each of these languages has its own strengths and weaknesses, and the choice between them often depends on the specific use case.