Topic: Filter list

[Robert98]

Hello everyone.
I want to filter a list of strings just like the filter function in VB script ,but when I launch the code, the original list shows up.
Can anyone tell me what i'm doing wrong . Here is my code:

Code: [Select]

(vl-load-com)
(defun c:Filter   (/ lst1 elem elem2)

  (setq lst1 '("Study" "moon" "teacher" "ball"))
  (foreach elem   lst1
    (setq elem2 (vl-string->list elem))
    (if   (= (member '(ascii "m") elem2) nil)
      (vl-remove elem lst1)
      (princ "\n")
    )
  )
  (princ lst1)
  (princ)
)

When I fire up the filter command ,I expect to get ("Study" "teacher" "ball") which is a list without strings that contain "m" letter in their structure.

[ronjonp]

When you remove the element, you need to set your lst1 variable like so:

Code - Auto/Visual Lisp: [Select]

1. (setq lst1 (vl-remove elem lst1))

Also ...

Code - Auto/Visual Lisp: [Select]

1. (member '(ascii "m") elem2)

will always return nil because of the ' ( quote ).


This can also be achieved using wcmatch like so ( keep in mind wcmatch is case sensitive ):

Code - Auto/Visual Lisp: [Select]

1. (vl-remove-if '(lambda (x) (wcmatch x "*m*")) '("Study" "moon" "teacher" "ball"))

[dgorsman]

Put another way, (vl-remove ...) returns a modified copy of the list and leaves the original intact.  Most LISP functions operate that way.

[ChrisCarlson]

Code - Auto/Visual Lisp: [Select]

1. (defun CC:remove ( lst1 wc /  )
2.         (setq lst2     
3.                 (vl-remove-if
4.                         '(lambda (x)
5.                                 (wcmatch x wc))
6.                         lst1
7.                 )
8.         )      
9. )
10.  
11.  
12. (defun c:remove_test ( / lst)
13.         (setq lst '("Study" "moon" "teacher" "ball"))
14.         (CC:remove lst "*m*")
15. (princ)
16. )
17.  

[Robert98]

Thank you everyone for all your replies.
I'll try what you suggested and i'll provide you with more details on the results.