Looking at the Java API I think I would want size() added to heeheehee's minimum for sets and lists. I'd consider contains() as a useful addition to lists but of mildly less importance.
Originally Posted by fronobulax View Post
I think a lot of these have existing analogues. To add to Veracity's examples:

set contains obj
foreach obj in set
remove set[obj];

list contains obj
foreach obj in list
remove list[index]

add / insert is the only one off the top of my head that would probably require special syntax (or a new function). Polymorphism could mean that we could even use append(aggregate, obj), although I think I'd prefer one of the names add / insert (preferably with the ability to specify index for lists, too).