YAML
YAML, which stands for Yet Another Markup Language, is a human-readable data serialization standard designed for all programming languages. Here are some detailed insights:
History and Development
- YAML was first proposed by Clark Evans in 2001. The initial version, 1.0, was released in 2004 by Evans, Ingy döt Net, and Oren Ben-Kiki YAML Specification 1.0.
- Version 1.1 was published in 2005, with minor changes to the original specification YAML Specification 1.1.
- In 2009, YAML 1.2 was released, incorporating several changes and aligning more closely with JSON YAML Specification 1.2.
Key Features
- Human Readable: YAML's syntax is designed to be easily understood by humans, which makes it ideal for configuration files where readability is important.
- Data Types: It supports a wide range of data types including scalars (strings, integers, floats), sequences (lists), and mappings (key-value pairs).
- Indentation-Based: YAML uses indentation to denote structure, similar to Python, making it very intuitive for users familiar with such syntax.
- Compatibility: YAML can be used in conjunction with JSON, as it has an official schema for describing JSON documents YAML Schema for JSON.
- Extensibility: Custom tags can be defined to extend YAML's capabilities, allowing for the inclusion of custom data types or directives.
Usage
YAML is commonly used in:
- Configuration files for applications, especially in DevOps and continuous integration/deployment environments.
- Data exchange between languages with different data representation formats.
- Serialization of data in web services and APIs.
- Documenting metadata in various systems, including content management systems like Jekyll or Hugo for static site generators.
Examples and Syntax
A simple example of YAML syntax:
---
- title: YAML Example
description: >
This is an example of how YAML
can be structured.
languages:
- Python
- Ruby
- JavaScript
Security Considerations
While YAML is generally safe, there have been concerns regarding the security of YAML parsers, particularly with regards to:
- Arbitrary code execution through the use of YAML tags or aliases.
- Denial of Service (DoS) attacks via deeply nested structures or very long documents.
It's recommended to use safe parsing options when loading YAML from untrusted sources YAML Security Considerations.
Related Topics