Re: Python syntax in Lisp and Scheme

Frode Vatvedt Fjeld wrote:

Scheme
(define vector-fill!
  (lambda (v x)
    (let ((n (vector-length v)))
      (do ((i 0 (+ i 1)))
          ((= i n))
          (vector-set! v i x)))))
>
Python
def vector_fill(v, x):
    for i in range(len(v)):
        v[i] = x
>
To me the Python code is easier to read, and I can't possibly fathom
how somebody could think the Scheme code is easier to read.  It truly
boggles my mind. [..]

 
The scheme example can only have been written by someone who is on the
outset determined to demonstrate that sexp-syntax is complicated. This
is how I'd write it in Common Lisp:
 
  (defun vector-fill (v x)
    (dotimes (i (length v))
      (setf (aref v i) x)))
 
As you can see, it matches the python example quite closely.

Why would any human want to match Python?

;; Racket
(define (vec-fill! v x)
  (vector-map! (const x) v))

;; Gauche Scheme
(define (vec-fill! v x)
  (vector-map! (lambda _ x) v))

(define vec (vector 2 3 4))

(vec-fill! vec 88)

vec
  ===>
#(88 88 88)

However, vector-fill! is already provided.

(vector-fill! vec 99)

vec
  ===>
#(99 99 99)

Multiply each element by 2:

(vector-map! (lambda(n) (* 2 n)) vec)

vec
  ===>
#(198 198 198)