jkaczo...@aol.pl wrote at 10/31/2011 12:58 PM:
Of course, I realize, that redefinition of the variables is not good
(functional) programming style but sometimes it's necessary. Is there
a possibility of such modifications without changing language?
You might wish to use a parameter, like in the example below.
#lang racket
(define current-counter (make-parameter 0))
(current-counter) ;==> 0
(current-counter 42)
(current-counter) ;==> 42
(current-counter (+ 1 (current-counter)))
(current-counter) ;==> 43
In this example, I have named your variable to start with "current-",
just by convention to emphasize that a variable is a parameter, but
that's not actually necessary.
--
http://www.neilvandyke.org/
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