From Newsgroup: comp.lang.lisp

Contrast the much more common

a[i] = b[n]

with

(setf (aref a i) (aref b n))

Would this be concise enough?

(a i b n)


Gauche Scheme

(define-method object-apply
((v0 <vector>) (i0 <integer>) (v1 <vector>) (i1 <integer>))
(vector-set! v0 i0 (ref v1 i1)))

(define a #(2 4 6 8))
(define b #(30 50 70 90))

gosh> a
#(2 4 6 8)

(a 2 b 3)

gosh> a
#(2 4 90 8)
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[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 --- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.lang.lisp

Wade Humeniuk wrote:

John Thingstad wrote:

(defun + (array) (loop for number across array summing number))
for a array.

Really?

CL-USER 1 > (reduce '+ #(1 2 3))
6

Gauche Scheme

(use gauche.sequence)

(fold + 0 #(1 2 3))
===>
6
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From Newsgroup: comp.lang.lisp

On 2025-06-18, B. Pym <Nobody447095@here-nor-there.org> wrote:

Wade Humeniuk wrote:

John Thingstad wrote:

(defun + (array) (loop for number across array summing number))
for a array.

Really?

CL-USER 1 > (reduce '+ #(1 2 3))
6

Gauche Scheme

(use gauche.sequence)

(fold + 0 #(1 2 3))

Alas, that could have been

(fold + #(1 2 3))

if they had only copied the good idea: when the initial accumulator is
not specified, infer it by calling the function without arguments.

With functions like +, you usually want the reduce accumulator to be the identity element, and the function can give it to you: (+) -> 0.

For the list appending monad, the empty list is the identity element,
and that's what (append) returns, so it works for that too:

(reduce #'append '((1) (2 3 4) (5))) -> (1 2 3 4 5)
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