[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Binding the same variable twice in a single form
Date: Thu, 12 Apr 90 17:41 EDT
From: barmar@Think.COM (Barry Margolin)
In the case of IGNORE variables, the portable way to do this is with the
(MULTIPLE-VALUE-BIND (VAL1 VAL2 X) (FUNC)
(DECLARE (IGNORE VAL1 VAL2))
<use X somehow>)
I can't think of any other reason why you would want to bind the same
variable twice in the same form, so the larger question should be moot.
Devils' advocate: How about the following (obviously kludgy) example?
(let* ((operation (get-operation))
(operation (if (null operation)
(status (if operation :safe :panic)))
... code that uses operation and status variables ...)
(defun get-a-number ()
(let* ((number (read))
(number (if (numberp number) number 0)))
It may not be nice programming style, but it works...
--- The Traveller -->|<-