;; Kathi Fisler ;; Powerpoint exercise ;; Stage -1 : Powerpoint without a language ;; print-string : string -> void ;; prints string and a newline to the screen (define (print-string str) (printf "~a~n" str)) ;; await-click : -> void ;; mimics a mouse click by waiting for the user to type a character (define (await-click) (read)) (begin (print-string "------------------------------") (print-string "Hand Evals in DrScheme") (print-string "Hand evaluation helps you learn how Scheme reduces programs to values") (print-string "------------------------------") (await-click) (print-string "------------------------------") (print-string "Example 1") (print-string "(+ (* 2 3) 6)") (await-click) (print-string "(+ 6 6)") (await-click) (print-string "12") (print-string "------------------------------") (await-click) (print-string "------------------------------") (print-string "Summary: How to Hand Eval") (print-string "Find the innermost expression") (await-click) (print-string "Evaluate one step") (await-click) (print-string "Repeat until have a value") (print-string "------------------------------") )