scsh-0.6/scheme/debug/wind-test.scm

53 lines
1.1 KiB
Scheme

; Copyright (c) 1993-1999 by Richard Kelsey and Jonathan Rees. See file COPYING.
"
The correct output looks something like this:
wind-1 f: 1
wind-2 f: 2
before-throw-out f: 3
unwind-2 f: 2
unwind-1 f: 1
after-throw-out f: top
wind-1 f: 1
wind-2 f: 2
after-throw-in f: 3
unwind-2 f: 2
unwind-1 f: 1
done f: top
"
(define (wind-test)
(let* ((f (make-fluid 'top))
(report (lambda (foo)
(write foo)
(display " f: ")
(write (fluid f))
(newline))))
((call-with-current-continuation
(lambda (k1)
(let-fluid f 1
(lambda ()
(dynamic-wind
(lambda () (report 'wind-1))
(lambda ()
(let-fluid f 2
(lambda ()
(dynamic-wind
(lambda () (report 'wind-2))
(lambda ()
(let-fluid f 3
(lambda ()
(report 'before-throw-out)
(call-with-current-continuation
(lambda (k2)
(k1 (lambda ()
(report 'after-throw-out)
(k2 #f)))))
(report 'after-throw-in)
(lambda () (report 'done)))))
(lambda () (report 'unwind-2))))))
(lambda () (report 'unwind-1))))))))))