Say you're using terraform with some poorly designed cloud thing, and you have a linked list of rules which also each needs their own index as an attribute cloudflare/terraform-provider-cloudflare#187. And now you have to insert an item somewhere close to the beginning of your 100 item chain. Do you go edit every number by hand?
# as delimiter (| doesn't work)* as count, (or \? or \+ or \{m,n})\= to specify using a :h sub-replace-expression:%s#priority = \(\d*\)#\=printf("priority = %d", submatch(1)+1)#
one day I will read the entire manual, one day...
:h sub-replace-special\U...\E make everything between uppercase\L...\E make everything between lowercaseCTRL-V <ENTER> newline:h character-classes