Re: CAR/CDR vs FIRST/REST

On 2024-07-02, B. Pym <No_spamming@noWhere_7073.org> wrote:

Barry Margolin wrote:
>

      (mapcan #'(lambda (x) (and (numberp x) (list x))) list)

 

      (loop for x in list
              when (numberp x) collect x)

 
I agree with this example.  Once I learned LOOP I never used the
above idiom again.

>
>
(filter number? '(a b c 1 2 3))
===>
(1 2 3)

In Common Lisp, filter has a funny name: remove-if-not.

  (remove-if-not #'numberp '(a b c 1 2 3))
  -->
  (1 2 3)

Likely because of the funny name, the function is marked deprecated,
which is silly.

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