Does Yorick pass by value, or what?
I think the manual does explain what happened to you. Yorick (and all similar interpreters) are actually “pass by five layers of indirection” languages (five is the actual number in Yorick — I counted once; less efficient interpreters have more, and I don’t see how to do with fewer), so it is a little difficult to characterize them as “pass by reference” or “pass by value”.
