Was reminded by the current challenges how often I've thought how nice it would be to have
list Indexing and Slicing based on the index location:
eg:
The main problem is = I not found fast index, because, I feel
assoc(1,list(...)) is too slow.
If you need then I need help, together can emulate JavaIndexer inside
or MoreMathematicallyLisp inside
(defun dfn_view_pnts(ljfour / $rr a b c d e f x)
/*c2s: b=getvar("VIEWSIZE"),
$rr=getvar("SCREENSIZE"),
c=car($rr),
d=cadr($rr),
a=b*c/d,
x=getvar(_T("VIEWCTR")),
x=trans(x,1,2);
c=list( car(x)-(a/2.0),cadr(x)-(b/2.0),0.0),
d=list( car(x)+(a/2.0),cadr(x)+(b/2.0),0.0),
c=trans(c,2,1),
d=trans(d,2,1),
$rr=(ljfour)?list(c,list(car(c),cadr(d),0.0),list(cadr(c),car(d),0.0),d):
(ljfour==4)?list(c,list(car(c),cadr(d),0.0),list(cadr(c),car(d),0.0),d):
list(c,d);
*/
$rr)