21 Dec
2007
21 Dec
'07
12:48 p.m.
On Fri, 21 Dec 2007 12:13:04 -0500, Justin Bailey
Given this function:
dropTest n = head . drop n $ [1..]
I get a stack overflow when n is greater than ~ 550,000 . Is that inevitable behavior for large n? Is there a better way to do it?
Justin
I'm curious as well. My first thought was to try the (!!) operator. Typing Prelude> [1..] !! 550000 overflows the stack on my computer, as does dropTest 550000. The code for (!!) is apparently as follows: xs !! n | n < 0 = error "Prelude.!!: negative index" [] !! _ = error "Prelude.!!: index too large" (x:_) !! 0 = x (_:xs) !! n = xs !! (n-1) Isn't this tail recursive? What is eating up the stack? Brad Larsen