Print Page - append with first argument optional nil

Title: append with first argument optional nil
Post by: HPW on March 21, 2005, 04:34:11 AM

Attempt to made a more alisp compatibel append:

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(define (append-nil alist )
	(if alist 
		(begin
		(setq _nlst alist)
		(dolist (_lst (args))(setq _nlst(append _nlst _lst))))
		(begin
		(setq _nlst (list ))
		(dolist (_lst (args))(setq _nlst(append _nlst _lst))))
	))

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> (setq a '(1 2))
(1 2)
> (append-nil a '(3)'(4)'(5))
(1 2 3 4 5)
> (append-nil b '(3)'(4)'(5))
(3 4 5)
>

Any better solution?

Title:
Post by: Lutz on March 21, 2005, 05:31:36 AM

Use 'apply append' instead of 'dolist':

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(define (append-nil alist)
  (if alist (append alist (apply append (args)))
            (apply append (args))))

Lutz

Title:
Post by: HPW on March 21, 2005, 06:33:53 AM

Thanks a lot. I have still the problem, to get the brain more lispisch.

;-)

Title:
Post by: Lutz on March 21, 2005, 07:51:46 AM

we can make it even shorter:

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(define (append-nil alist)
  (append (if alist alist '()) (apply append (args))))

Lutz

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Forum => newLISP in the real world => Topic started by: HPW on March 21, 2005, 04:34:11 AM