Web Symbols
Web Symbols is a framework built on top of the platform's Symbol API. Its primary use is to reduce boilerplate when building support for web technologies, however one can take advantage of it for any kind of technology.
Web Symbols API reduces work needed to provide reference resolution, find usages, documentation and rename refactoring. It also provides an efficient JSON format (Web Types) for static symbol definitions. Web Symbols core advantage, however, is the ability to evaluate symbol patterns.
Web frameworks tend to have custom syntaxes to enable various things, e.g. through HTML attribute name (see Model Queries example to see Vue directive syntax). The pattern evaluator is able to recognize symbols in different sections of the element name and provide reference resolution, documentation, usage occurrence, etc. It also supports rename refactoring for symbols originating from source code. Another advantage is the flexibility of Web Symbols query. It is very easy to contribute new symbols from various sources, which works perfectly for multi-sourced (e.g. source code, library code, Web Types) applications.
Web Symbols API is not designed to create a support for new languages, but to rather work on meta level, to support frameworks or libraries, which are giving additional meaning to the existing language features. Currently, IDEs provide built-in integration for following language features (see Web Symbols Integration with Language Features):
HTML: elements, attributes and attribute values
CSS: properties, custom properties, functions, classes, pseudo-elements, pseudo-classes and parts
JavaScript: string-literals, object properties, object literals and symbols (in JavaScript)
There's also the option to write integration for other languages.
Web Symbols framework provides also a convenient way to manage enablement of features through WebSymbolsContext API.
The following sub-pages provide information on how to implement Web Symbols for plugins and how to define them statically through JSON schemas: