So I need to implement again the assembly manager in the IDE. which will allow you to add your own C# libraries (DLLs) and then the answer would be yes, but from within the engine's language, like this:
C#:
public void DoSomething(Exp.Instance? callingInst, Exp.IValue?[] args)
{
...
}
Exp:
doSomething("hello")
There is already a relection-based way to call C# functions from my language, i call it "extern classes":
extern class File = "System.IO.File"
println(File.readAllText(filePath))
it can also be used with non-static classes, and you can use new(...) expressions on them, and "is" tests and access properties and so on... it SHOULD feel like a normal Exp class. The only exception is that it does not fit to performance-critical contexts, because it uses the slow reflection APIs of C#. but it's already working, unlike the assembly manager feature that is not implemented yet but will allow fast invocations.