Ask HN: `Bind` to widget vs. `action:sender ` architecture – Tk vs. Cocoa

Hi all! I'm using Tk for the first time and am comparing it with my experience using Apple's Cocoa.

Though I love how fast Tk is to get up and running—I'm sort of missing the flexibility provided by `sender:action`—not to mention that it brings up a lot of questions regarding app architecture.

Can you help clear out what the common nomenclature is between these 2 different architectures? What kind of problems should I expect as I develop between the 2?