C# grammar for tree-sitter based upon the Roslyn grammar with changes in order to:

• Deal with differences between the parsing technologies
• Work around some bugs in that grammar
• Handle #if, #else, #elif, #endif blocks
• Support syntax highlighting/parsing of fragments
• Simplify the output tree
• Reduce parser state count and complexity
• Be in-line with tree-sitter's convention where applicable

Comprehensive supports C# 1 through 14.0 with the following exceptions:

• async, var and await cannot be used as identifiers everywhere they are valid
• File-based apps preprocessor directives (#:property, #:package, #:sdk, #:project) are not yet recognized

• Official C# 8 Draft Language Spec provides chapters that formally define the language grammar.
• Roslyn C# language grammar export
• SharpLab (web-based syntax tree playground based on Roslyn)