Sorting with secondary parameters in assoc list

I don't believe there is a multi column sort. One thougt would be: after you do the sortcar you'd need to iterate over the list and create an array or table of sublists based on the "car". Then modify the sublist so the elements are '(b '(a b), then you can sortcar on the sublist. Once all the sublists are sorted you'll need to put them back to '(a b) and then rebuild the original list.

Just a thought

Craig

Use "sort" which allows you to specify a sort function. It is passed two arguments and should return non-nil if a<b and nil if a>= b  Create one that does something like:

 (defun mysortfunc (a b)

 (if  (equal (car a) (car b) )  ( return (lessp (cadr a) (cadr b) ) )  

 (return (lessp (car a) (car b) ) )

)

 I am doing this from memory and may not have gotten the syntax exactly right.  It the sort is backwards, replace lessp with greaterp.

Hi RFDTeradyne,

Yes, the function works well. Thanks.

Define the sorting algor as:

procedure( mySortFunc(a b)
prog( ()
if( eq(car(a) car(b)) then
 return(cadr(a)<cadr(b)) else
 return(car(a)<car(b))
) ; end if
) ; end prog
) ; end proc mySortFunc

and try:

Skill> sort( list('(7 45) '(7 56) '(5 23) '(24 13) '(25 1) '(6 2) '(7 5) '(24 8)) 'mySortFunc)

-> ((5 23)  (6 2) (7 5) (7 45) (7 56) (24 8) (24 13) (25 1))