I've always wondered about nullary versus 0-ary. My logic, ignoring this, is (since we can have multiple argument lists, I included a list of arities to further illustrate):

• def m(x: Any, y: Any) is binary / 2-ary (List(2))
• def m(x: Any) is unary / 1-ary, and (List(1))
• def m() is zero-ary / 0-ary. (List(0))
• def m is null-ary (Nil)

No? 🤔

I tend to say "parameterless" for def m.

@adriaanm if you don't have more additions, I can merge

(maybe we can include the list you wrote somewhere in that documentation page for reference?)

for me this is good to merge, i guess people (the target audience of this page) don't care too much about my thinking on the naming :-)