Language Ideas

do you guys ever have ideas for features in programming languages that you have never seen implemented but would like to?
i'm sure some of you have. i can't be the only one.
share them here.
i'll start with an idea i had a little while ago; i wouldn't be surprised if some language such as perl had already thought of it though.

have you ever been stuck writing long if statements along the lines of: if(c == x || c == y || c == z)?
sure, it might not look so bad in this case since it's rather short. but what if you could abbreviate it?
something like: if(c == ||(x,y,z)), or perhaps if(c == (x || y || z)), or even if((x,y,z)||==(a,b,c)), which would expand to if(x == a || y == b || z == c).
wouldn't that be a nice little time saver?

>>44
Hmm, M-x slime-edit-definition seems to be roughly what I'm after. Does it require me to stop and restart the interpreter? or can I immediately start working with the new definitions?
>>45
DrScheme is what I've been using (or occasionally running and inferior scheme with quack-mode) and it's explicit stop-and-run is no better that having to use reload in python although it is more convenient.