Teachpacks for How to Design Programs

# Guess GUI

### guess-gui.ss

The teachpack `guess-gui.ss` implements three functions:

- `control : N -> symbol`
  to read out the i-th guess choice, starting with 0
- `view : (union string symbol) -> true`
  to display its argument in the message panel
- `modelT = (button% event% -> true)`
  `connect : modelT -> true`
  to connect a controller with the Check button
  displays frame

  Example:

      (connect (lambda (e b)
                 (begin
                   (printf "0th digit: ~s~n" (control 0))
                   (view (control 0)))))