Edit: After reading the OP, I realized that my example of uppercasing constant definitions, can be simpler with this vim command, which doesn't shell out to th

Edit: After reading the OP, I realized that my example of uppercasing constant definitions, can be simpler with this vim command, which doesn't shell out to the tr command: gUG (uppercase U in the command, as opposed to the OP's use of guG - lowercase u).