Very interesting, thank you.
As often happens in the Monastery, it seems that you read my mind :).
Just few days ago, I was reading the chapter in
Structure and Interpretation of Computer Programs
concerning streams and delayed evaluation, thinking about a Perl implementation. I strongly suggest buying that book, it's really worth
reading, and this isn't the first it is mentioned here.
Update: hey, I noticed this is my 100th post. I'm specially glad to see that concerns Lisp-ish topics :) I'd never said that when I entered Perlmonks :)