Re: [racket-users] Re: Question about Racket design philosophy: returning (void)

[Gustavo Massaccesi]

For debuging I like

  (define (show x)
(display x)
x)

  (define (noshow x)
x)

For example in

  (define (average x)
(/ (+ (car x) (show (cdr x))) 2))

noshow is useful to turn on/off them fast.

But this is different from the convension of << in the streams of C, that
return the stream instead of the value, something like

  (<< (<< cout "Hello ") "Word!")

Gustavo

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[racket-users] Re: Question about Racket design philosophy: returning (void)

[Jack Firth]

Racket's also flexible enough that you can say "to hell with void, I want 
function chaining" if you decide it's more appropriate:

(require fancy-app) ;; now (+ _ 1) means (lambda (v) (+ v 1))
(require point-free) ;; now (~> x f g h) means (h (g (f x)))

;; makes voidful procedures return their argument
(define ((action! proc) v)
  (proc v)
  v)

;; like ~>, but turns all procedures into actions first
(define (act~> v . procs)
  (apply ~> v (map action! procs)))

;; voila!
(act~> (make-vector 5)
   (vector-fill! _ 'blank)
   (vector-set! _ 2 'grapefruit)
   (vector-set! _ 0 'watermelon)
   (vector-map! symbol->string _)
   (vector-sort! _ stringhttps://groups.google.com/d/optout.