Modern Signature Help API?

[tgjones]

Are there any plans to do for Signature Help, what has already been done for Quick Info and Completion? i.e. something like a IAsyncSignatureHelpSource, IAsyncSignatureHelpSourceProvider, etc., built on the modern commanding APIs.

At the moment a fair amount of boilerplate is still required to create a robust implementation of signature help. It would be great to see some of this boilerplate move down from Roslyn to VS :)