(defun avg (args)
(loop for x in args
for l upfrom 1
summing x into tot
finally (return (/ tot l))))

Gauche Scheme

(use gauche.collection) ;; fold2

(define (add&count n sum cnt) (values (+ sum n) (+ cnt 1)))

(define (avg nums)
(apply /
(values->list
(fold2
add&count
0 0
nums))))

(avg '(20 30 40 50 60 70 80))
===>
50

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 6/15/2024 9:39 PM, B. Pym wrote:

(defun avg (args)
(loop for x in args
for l upfrom 1
summing x into tot
finally (return (/ tot l))))

Gauche Scheme

(use gauche.collection) ;; fold2

(define (add&count n sum cnt) (values (+ sum n) (+ cnt 1)))

(define (avg nums)
(apply /
(values->list
(fold2
add&count
0 0
nums))))

(avg '(20 30 40 50 60 70 80)) ===> 50

Nice... Here's a more boring version:


(define (ave x)
(let ((L (length x)))
(if (> L 0)
(/ (fold + 0 x) L))))

(define (Pave x) (format #t "~% ~S ~S ~%" x (ave x)))

(Pave '(1 2 3))
(Pave '(1 2 3 4))
(Pave '(1))
(Pave '())

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 6/16/2024 11:28 AM, HenHanna wrote:

On 6/15/2024 9:39 PM, B. Pym wrote:

     (defun avg (args)
       (loop for x in args
           for l upfrom 1
           summing x into tot
           finally (return (/ tot l))))

Gauche Scheme

(use gauche.collection) ;; fold2

(define (add&count n sum cnt) (values (+ sum n) (+ cnt 1)))

(define (avg nums)
   (apply /
     (values->list
       (fold2
         add&count
         0 0
         nums))))

(avg '(20 30 40 50 60 70 80))     ===>   50

Nice...    Here's a more boring version:

(define (ave x)
  (let ((L (length x)))
    (if (> L 0)
      (/ (fold + 0 x) L))))

(define (Pave x)   (format #t "~%    ~S  ~S  ~%" x (ave x)))

(Pave  '(1 2 3))
(Pave  '(1 2 3 4))
(Pave  '(1))
(Pave  '())

(define-macro (ave x)
`(/ (+ ,@ (map (lambda (n) `(+ ,@ (make-list n 1))) (cadr x)))
(+ ,@ (map (lambda (n) 1) (cadr x)))))

(print (ave '(1)))
(print (ave '(1 2 3)))

gosh> (macroexpand '(ave '(1 2 3)))
==> (/ (+ (+ 1) (+ 1 1) (+ 1 1 1)) (+ 1 1 1))

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2024-06-16, HenHanna <[email protected]> wrote:

On 6/15/2024 9:39 PM, B. Pym wrote:

(defun avg (args)
(loop for x in args
for l upfrom 1
summing x into tot
finally (return (/ tot l))))

Gauche Scheme

(use gauche.collection) ;; fold2

(define (add&count n sum cnt) (values (+ sum n) (+ cnt 1)))

(define (avg nums)
(apply /
(values->list
(fold2
add&count
0 0
nums))))

(avg '(20 30 40 50 60 70 80)) ===> 50

Nice... Here's a more boring version:

(define (ave x)
(let ((L (length x)))
(if (> L 0)
(/ (fold + 0 x) L))))

(define (Pave x) (format #t "~% ~S ~S ~%" x (ave x)))

(Pave '(1 2 3))
(Pave '(1 2 3 4))
(Pave '(1))
(Pave '())

This is the TXR Lisp interactive listener of TXR 294.
Quit with :quit or Ctrl-D on an empty line. Ctrl-X ? for cheatsheet.
Evidence of amphoric Lisp macros was recently found in ancient clay
jars.

[[callf / sum len] '(1 2 3 4)]

2.5

callf: return a function which:

- applies the second and subsequent functions given to callf (here sum
and len) to its arguments.
- applies the first argument of callf (here /) to the resulting
values.
- returns the resulting value

--
TXR Programming Language: http://nongnu.org/txr
Cygnal: Cygwin Native Application Library: http://kylheku.com/cygnal
Mastodon: @[email protected]

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 2024-08-09, steve g <[email protected]> wrote:

"B. Pym" <No_spamming@noWhere_7073.org> writes:

< > (defun avg (args)
< > (loop for x in args
< > for l upfrom 1
< > summing x into tot
< > finally (return (/ tot l))))

Gauche Scheme

(use gauche.collection) ;; fold2

(define (add&count n sum cnt) (values (+ sum n) (+ cnt 1)))

(define (avg nums)
(apply /
(values->list
(fold2
add&count
0 0
nums))))

(avg '(20 30 40 50 60 70 80))
===>
50

(loop for x in '(1 2 3 4 5)
summing x into max
counting x into cnt
finally (pprint (/ max cnt)))

[[callf / sum len] '(1 2 3 4 5)]

3.0

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

(defun avg (args)
(loop for x in args
for l upfrom 1
summing x into tot
finally (return (/ tot l))))

(define (avg xs)
(do ((sum 0 (+ (pop! xs) sum))
(i 0 (+ 1 i)))
((null? xs) (/ sum (max 1 i)))))

(avg '())
0
(avg '(2))
2
(avg '(2 3 4))
3

--
[T]he problem is that lispniks are as cultish as any other devout group and basically fall down frothing at the mouth if they see [heterodoxy].
--- Kenny Tilton
The good news is, it's not Lisp that sucks, but Common Lisp. --- Paul Graham

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 8/7/2025 11:21 AM, B. Pym wrote:

(defun avg (args)
(loop for x in args
for l upfrom 1
summing x into tot
finally (return (/ tot l))))

(define (avg xs)
(do ((sum 0 (+ (pop! xs) sum))
(i 0 (+ 1 i)))
((null? xs) (/ sum (max 1 i)))))

(avg '())
0

That, of course is an error. Return nil or signalling the condition
would be more to the point. This looks like a COBOL implementation.

(avg '(2))
2
(avg '(2 3 4))
3--

Jeff Barnett

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)