A student's question

My teacher keeps drilling into our collective heads that using the break command is harmful, and that if we wish to terminate a loop early it would be far better to create a boolean variable, set it to 0, and add a condition to the head of the loop, and set the boolean variable to 1 when a break is needed. Note that this way you actually have to check this every single loop (where it is not needed almost every time) as well as waste a command to reset the boolean in case it was set to true.

Is there a reason to this?

>>77
it's
Also,
(define this-function
  (make-parameter #f))

(define-syntax-rule (defun f args . body)
  (define (f . args)
    (parameterize ((this-function 'f))
      . body)))

(defun f () (this-function))
(f)