Use map-<unique> to warn users if yankstack is clobbering maps

[idbrii]

If yankstack used <unique> (see :help map-<unique>), then users would get a warning instead of their maps (like Y or #9) being clobbered.

I'm not sure if there's a way for you to tell users to call yankstack#setup() in their vimrc for more user friendliness. Maybe you could use a try?

[maxbrunsfeld]

Yeah, I think this is a good idea. Using <unique> sounds the easiest. Or, we could use maparg to check if any mappings have been defined, and display a more specific error message.

[idbrii]

I no longer use yankstack, so this issue no longer affects me. Feel free to reopen if it's a case you want to consider.