CDE

Task/Exceptions/Racket/exceptions.rkt

@@ -0,0 +1,13 @@
+#lang racket
+
+;; define a new exception type
+(struct exn:my-exception exn ())
+
+;; handler that prints the message ("Hi!")
+(define (handler exn)
+  (displayln (exn-message exn)))
+
+;; install exception handlers
+(with-handlers ([exn:my-exception? handler])
+  ;; raise the exception
+  (raise (exn:my-exception "Hi!" (current-continuation-marks))))