Re: efficiently accumulating values

liyer.vijay@xxxxxxxxx writes:

liyer.vijay@xxxxxxxxx wrote:
[snip my own stuff]

Hi,

I found the reference in PCL (Peter, if you're reading this, thanks)
to VECTOR-PUSH-EXTEND which dramatically reduces time to 0.346
seconds. Here is the program:

(defun find-words (graph)
"Given GRAPH find all possible words."
(destructuring-bind (m n) (array-dimensions graph)
(loop with result = (make-array 0 :adjustable t :fill-pointer 0)
as i from 0 to (1- m)
do (loop as j from 0 to (1- n)
do (loop as word in (get-words graph i j)
if (and (zerop i) (zerop j))
do (vector-push-extend word result)))
finally (return (coerce result '(or cons list))))))

However, I'd still like to know if there's a better way, and since I
didn't mention it in my last post, any suggestions, comments,
criticisms on coding style, programming are greatly appreciated.

I was about to suggest vector-push-extend. I have only glanced over your code
but I'd think the next thing you could do is pass the vector in to get-words
to be destructively modified there.
.

Relevant Pages

  • Re: efficiently accumulating values
    ... to VECTOR-PUSH-EXTEND which dramatically reduces time to 0.346 ... "Given GRAPH find all possible words." ... do (loop as word in (get-words graph i j) ... if (and (zerop i) ) ...
    (comp.lang.lisp)
  • Re: efficiently accumulating values
    ... to VECTOR-PUSH-EXTEND which dramatically reduces time to 0.346 ... (defun find-words (graph) ... "Given GRAPH find all possible words." ... Unless get-words is not a pure function. ...
    (comp.lang.lisp)