less/less.js
Less.js
Less.js is a CSS preprocessor and compilation engine that transforms a dynamic stylesheet language into standard CSS for web browser rendering. It functions as a tool to compile extended styling syntax, providing variables, mixins, and functions to create maintainable stylesheets.
The project includes a source map generator that creates mapping files to link compiled CSS output back to the original source code for debugging. It allows for the integration of custom plugins and functions to automate the generation of final stylesheets within a build process.
The engine supports the compilation of container queries, the management of CSS layers, and the interpolation of variables within selectors and at-rules. It also provides capabilities for implementing custom functions for math, lists, and logical operations.
Features
- Stylesheet Compilation Engines - Provides a full compilation engine that transforms advanced styling syntax and plugin-modified ASTs into browser-compatible CSS.
- CSS - Compiles extended CSS syntax, including loops and conditionals, into standard browser-compatible CSS.
- Compiler Functions - Implements built-in and custom functions for math, lists, and logical operations during the build.
- Styling Languages - Introduces a dynamic stylesheet language with a custom syntax for variables, mixins, and functions to improve maintainability.
- Variable Substitutions - Replaces named variables with their assigned values across a scoped stylesheet hierarchy.
- Dynamic Style Compilation - Transforms advanced styling syntax into standard CSS to implement complex design patterns.
- Interpolation Mechanisms - Embeds variables and expressions directly into selectors and at-rules during the compilation process.
- CSS Preprocessors - Implements a preprocessor that transpiles modular stylesheet files with variables and mixins into standard CSS.
- Recursive Descent Parsers - Uses a recursive descent parser to convert raw stylesheets into a hierarchical abstract syntax tree.
- AST Transformation Tools - Implements a transformation pipeline that manipulates the stylesheet via an abstract syntax tree.
- Build Pipeline Plugins - Provides a plugin architecture that intercepts and transforms assets during the CSS compilation lifecycle.
- Source Map Generators - Generates source maps that link compiled CSS output back to the original source files for debugging.
- Expression Evaluators - Processes math and logic expressions within the stylesheet using a dedicated evaluation engine.
- Plugin Integrations - Integrates custom plugins into the compilation pipeline to modify the final styling output.
- Selector Interpolation - Enables flexible styling rules through selector interpolation and case-insensitive attribute selectors.
- Container Query Utilities - Generates styles based on the size or state of parent elements using container queries.
- CSS Pipeline Processing - Automates the generation of final stylesheets using a plugin-based transformation pipeline.
- CSS Layout Systems - Implements responsive designs using modern CSS features like container queries and layer rules.
- CSS Layer Configurations - Controls the cascade priority and specificity of styles using CSS layer at-rules.
- Parsing Tools - Less dynamic stylesheet language.
- CSS Preprocessors - Backwards compatible CSS extension with extra features.
