README.md

C# Examples

The C# examples use lang-forge generate --target csharp and build with the local .NET SDK. They target net10.0, so the .NET 10.0 SDK is required for run and test targets.

Run one example:

make -C examples/csharp/calc run
make -C examples/csharp/datakeeper run
make -C examples/csharp/draw run
make -C examples/csharp/vehicle-report run

Run generated-code checks:

make -C examples/csharp/calc test
make -C examples/csharp/datakeeper test
make -C examples/csharp/draw test
make -C examples/csharp/vehicle-report test

Generated scanner/parser files are written to Generated/ with .g.cs filenames and ignored by Git. Each project keeps handwritten reducer and demo code outside Generated/.

The Makefiles include shared fragments from examples/mk and default to shared valid fixtures under examples/testdata. For a smaller copyable starter project, use examples/templates/csharp/mini-compiler. For reusable parser library code, use examples/templates/csharp/library-dsl.

C# examples prefer source-based parsing with new Scanner(sourceText) passed to generated overloads such as Parser.ParseWithReducer(new Scanner(sourceText), reducers) or Parser.ParseRecovering(new Scanner(sourceText)). Scanner.Tokenize(...) and token-list parse APIs remain useful for debugging and tests. Reusable examples convert generated values and diagnostics into domain ParseResult<T> values at the facade boundary; generated code stays container-agnostic, while handwritten semantics/facades are the right place for policies, services, and DI.

When learning from a C# example, read *.lf first, then the handwritten Semantics or Program.cs reducer wiring, then any Parsing facade. Generated *.g.cs files are intentionally separated under Generated/; after running make generate, they show the token enum, scanner DFA tables, parser ACTION/GOTO tables, and typed reducer context records that the handwritten code uses.

For a reusable compiler-style starter, use examples/templates/csharp/layered-compiler. It keeps Generated/ isolated, puts domain records under Ast/, maps typed reducer contexts in Semantics/, exposes IMiniCompilerParser plus ParseResult<T> from Parsing/, and keeps Program.cs as a thin demo entrypoint. It also shows how to inject semantic policies without making generated code depend on a DI container.

For the recommended handwritten C# reducer, parser facade, reusable library, dependency-injection, and multi-parser shapes, read Handwritten Integration Guide.