Add ability to execute/evaluate workspace in separate thread

[maciejmatuszak]

• Add EvaluateAsync methods to Workspace
• Use CancelationTokenSource as a method to cancel execution
• check status of cancelation token after each block evaluation

[maciejmatuszak]

@richorama I was playing with Evaluate method today. I do not understand why there two Evaluate implementations
public virtual object Evaluate(Context context) in Workspace class
static object Evaluate(this Workspace workspace, IDictionary<string,object> arguments = null) and in Extensions

I would just overload the method in Workspace, I think I am missing something?

Maciej

[richorama]

Hey @maciejmatuszak I don't think there's any special reason, other that the extension method is for convenience. It could be an overload.

I think you're on the right track. I would suggest that we drop the non-async evaluate, and make everything async (as you don't know what might be further down the program). I'm happy to help out with some of the work here.