Question

(define (number-checker)
     (define userinput (read))
     (cond
        [(eof-object? userinput) print-fun)]
        [else
          (set!  tries (+ 1 userinput))
          (number-checker)]))

If i want to quit the program what would i have to write in order for program to go to print-fun?

Answer 1

It’s not compiling for me (using Racket):

also after fixing the typo:

If I understand correctly it’s supposed to read the user-input from prompt and bail-out when the “end of file” character arrives. But, this code will definitely won’t work. what is print-fun ? etc.

UPDATE:
The working code is:

#lang racket
(define (number-checker)
     (define userinput (read))
     (define tries 'a)
     (cond
        [(eof-object? userinput) 'print-fun]
        [else
          (set!  tries (+ 1 userinput))
          (number-checker)]))

It works like this:

UPDATE 2:
another screenshot that shows the eof button that appears after you run (number-checker):