Re: Element-Relative Sequence Insertion

[Marc Tfardy <bum@cyk.cyk>]

 >>> It does, but you have to decrypt it first.
 >> (defun insert-after (elt lst new)
 >>   (cond ((null lst)
 >>          '())
 >>         ((eq new (car lst))
 >>          (cons (car lst) (cons elt (cdr lst))))
 >>         (t
 >>          (cons (car lst) (insert-after elt (cdr lst) new)))))
 >>
 >> (defun insert-before (elt lst new)
 >>   (cond ((null lst)
 >>          '())
 >>         ((eq new (car lst))
 >>          (cons elt lst))
 >>         (t
 >>          (cons (car lst) (insert-before elt (cdr lst) new)))))
 >>
 >> What is the price? ;-)
 >
 > What's the point in renaming the parameters and introducing bugs?
 >
 > Check again the order of the parameters!

OK, this was a mistake. But it's "only" cosmetics ;-) I tested this
with:

(insert-after 'X '(a b c) 'b)
(a b X c)

(insert-before 'X '(a b c) 'b)
(a X b c)

so I unintended assumed your right arguments order ;)


 > Notice that (eq 3.141592 3.141592) --> nil ; which is the reason why
 > eql should be used by default.

Yes, this was my big fault. Sorry.


 > And bad points for not being able to use rot13.
 >
 > You lose.   :-)

Oh shit... :-)

regards
Marc