I recently assembled a tool:

It’s a helper for scripting in C#. It watches a directory with C# files for changes, and whenever a file changes it gets compiled into its own executable. You can install it as an always-on service, and it comes with an opinionated set of utilities to make scripting easier.

Why?

C# the language has recently become much more succinct (top-level statements, global usings); seems like it should be good for writing fast, maintainable scripts! But the tooling around the language still isn’t quite there yet; you need a .csproj project file for every program, and dotnet run often takes a second or 2 to start up, it’s not (yet) optimized for scripting use. This proposal should help in many ways (upvote it!) but who knows if or when it will be done.

Also, this has been stuck in my head for a while:

My OS has no notion of build system. It has all the source code on it and I can edit anything and run the command again with the change immediately applied. Interpreter or compiler, I don’t know, that’s an implementation detail. Then I wake up.

Give it a spin

Instructions, source and pre-built executables for Linux+macOS+Windows are available on GitHub.