CS 342 Lecture -*- Outline -*-

* the SASL interpreter

** thunks = expression + environment
	note: different case from closure
		in a closure expression has to be lambda (parameters + body)

*** printing thunks
	prValue doesn't get their value...

*** evaluation
	evalList makes list of thunks
	variables used as expressions are forced (evalThunk,	 p. 169)
		note how memoization is done
		can a thunk ever evaluate to a thunk?
			yes, e.g., (car l) where l denotes a thunk
				but applyValueOp calls evalThunk
				 before returning a car or cdr
			what about x where x denotes
				the thunk <| y, {y |->1} |>?