Not quite at a single .cs file, but there is the third-party dotnet-script [1] installed as a global tool to run .csx files. That's been around longer that C# l

Not quite at a single .cs file, but there is the third-party dotnet-script [1] installed as a global tool to run .csx files. That's been around longer that C# language support for top level statements. [1] https://github.com/filipw/dotnet-script https://github.com/filipw/dotnet-script