tree-sitter-c-sharp

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

Status

Comprehensive support for C# exists with the following exceptions:

• [ ] async, var and await cannot be used as identifiers

C# 8.0 (complete)

• [x] readonly members
• [x] Default interface methods
• [x] switch expressions
• [x] switch property patterns
• [x] switch tuple patterns
• [x] static local functions
• [x] Nullable reference types
• [x] Null-forgiving operator
• [x] Null-coalescing assignment
• [x] using statement without braces

C# 9.0 (complete)

• [x] Covariant returns
• [x] Extending partial methods
• [x] Extension GetEnumerator
• [x] Function pointers
• [x] Init properties
• [x] Lambda discard parameters
• [x] Local function attributes
• [x] Module initializers
• [x] Native integers
• [x] Patterns
  • [x] Simple type patterns
  • [x] Relational patterns
  • [x] Logical patterns
• [x] Records
• [x] Skip Locals Init
• [x] Static anonymous functions
• [x] Target-typed conditional expression
• [x] Target-typed new
• [x] Top-level statements

C# 10.0

• [x] global using directives
• [x] File-scoped namespace declaration
• [x] Extended property patterns
• [x] Allow const interpolated strings
• [x] Record types can seal ToString()
• [x] Allow both assignment and declaration in the same deconstruction
• [x] Allow AsyncMethodBuilder attribute on methods
• [x] Record structs

References

• Official C# 6 Language Spec provides chapters that formally define the language grammar.
• Roslyn C# language grammar export
• SharpLab (web-based syntax tree playground based on Roslyn)