SRFI 226: Control Features

I read this after perusing the linked resources last time it surfaced, and although I'm no expert, I really like this solution. I'd love to hear from the Scheme implimentors and macro-writers who have actually used call/cc. The control offered over the scope of a continuation, reminding me (model-wise) of a patchset cherry-picked off the head of a git branch, appesrs to soundly address preformance concerns, while the ability to return a value to the continuation's call-site looks like a huge advantage.

&quot;Finally, a primitive (call-in-continuation) is provided that allows calling a procedure in a given continuation instead of just delivering values to it.&quot;<p>can anyone add some language about what this is? I read this and the section on it, and remain deeply confused

<i>Finally, promises as defined in this specification can deliver multiple values when forced, an extension too natural to ignore</i><p>Oh yes, excellent, looking forward to playing around with multiple-value lazy streams (srfi-41).