Topic: sort a list of strings

[Coder]

Hello guys.

I have a problem with sorting a list of strings based on the second item of the list ascendingly.

Code: [Select]

(setq the_list '(("Top Beam" "200x150") ("Left Beam" "200x100") ("Left Beam" "150x200") ("Bottom Beam" "225x75")
                 ("Bottom Beam" "100x200") ("Right Beam" "45x35") ("Bottom Beam" "100x175") ("Right Beam" "55x25")))


Code: [Select]

(vl-sort the_list
         '(lambda (x y)
            (< (cadr x) (cadr y))
          )
)
The result is not correct.

Thank you.

[Dlanor]

Try this. It uses a string->list function

Code - Auto/Visual Lisp: [Select]

1. (defun _split (str char / pos lst )
2.   (while (vl-string-position (ascii char) str)
3.           (setq lst (cons (substr str 1 (setq pos (vl-string-position (ascii char) str))) lst)
4.                 str (substr str (+ 2 pos))
5.           );end_setq
6.   );end_while
7.   (setq lst (vl-remove-if '(lambda (x) (= x "")) (reverse (cons str lst))))
8. );end_defun
9.  
10. (setq the_list '(("Top Beam" "200x150") ("Left Beam" "200x100") ("Left Beam" "150x200") ("Bottom Beam" "225x75")
11.                  ("Bottom Beam" "100x200") ("Right Beam" "45x35") ("Bottom Beam" "100x175") ("Right Beam" "55x25")))
12.  
13. (vl-sort the_list '(lambda (x y / a b)
14.                      (setq a (_split (cadr x) "x") b  (_split (cadr y) "x"))
15.                      (if (= (atoi (car a)) (atoi (car b))) (< (atoi (cadr a)) (atoi (cadr b))) (< (atoi (car a)) (atoi (car b))))
16.                   )
17. )
18.  

[Lee Mac]

I might suggest something along the lines of the following:

Code - Auto/Visual Lisp: [Select]

1. (defun mysort ( l )
2.     (mapcar '(lambda ( n ) (nth n l))
3.         (vl-sort-i (mapcar '(lambda ( x ) (read (strcat "(" (vl-string-subst " " "x" (cadr x)) ")"))) l)
4.            '(lambda ( a b )
5.                 (if (= (car  a) (car  b))
6.                     (< (cadr a) (cadr b))
7.                     (< (car  a) (car  b))
8.                 )
9.             )
10.         )
11.     )
12. )

Code - Auto/Visual Lisp: [Select]

1. _$ (mysort the_list)
2. (
3.     ("Right Beam"    "45x35")
4.     ("Right Beam"    "55x25")
5.     ("Bottom Beam" "100x175")
6.     ("Bottom Beam" "100x200")
7.     ("Left Beam"   "150x200")
8.     ("Left Beam"   "200x100")
9.     ("Top Beam"    "200x150")
10.     ("Bottom Beam"  "225x75")
11. )

[Coder]

Thank you Dlanor and Lee.

Both works great.