Roslyn VS JSIL

.NET is a little smarter about switch code generation these days: https://github.com/dotnet/roslyn/pull/66081

Recently, while creating some experimental C# source code generators (xafero/csharp-generators), I was just concatenating strings together. Like you do, you know, if things have to go very quickly. If you have a simple use case, use a formatted multi-line string or some template library like scriban. But I searched for a way to generate more and more complicated logic easily - like for example, adding raw SQL handler methods to my pre-generated DBSet-like classes for my ADO.NET experiment. You could now say: Use Roslyn and that's really fine if you look everything up in a website like SharpLab, which shows immediately the syntax tree of our C# code.

At runtime, the Case C# expressions are embedded into a function and dynamically compiled into an assembly using the Roslyn C# compiler. Then the function that contains the expression is called (e.g. CaseAvailableFunction.Availablle()). At runtime, the function provides various methods to access stored case values as well as the current input data.

For those interested in the details, this was based on the original Stardew source code, shaved down for portability, and converted to a browser app using JSIL with lots of tweaking and love.