<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
<tt>Thanks for all the advises so far.<br>
<br>
Ok, here's my monster that need to be timed in order to make a
comparison:<br>
(it's about the control digit of SEDOL numbers </tt> <a
class="moz-txt-link-freetext" href="http://en.wikipedia.org/wiki/SEDOL">http://en.wikipedia.org/wiki/SEDOL</a>
):<br>
<tt><br>
<br>
knip _ [] = Nothing<br>
knip k xs = Just (splitAt k xs)<br>
<br>
ip xs = sum . zipWith (*) xs<br>
<br>
an = ['0'..'9']++['A'..'Z']<br>
<br>
s = take 841 $ cycle "0987654321"<br>
f = \xs -> xs ++ [(sna!!).ip [1,3,1,7,3,9]. map (flip (fromJust .)
an . findIndex . (==))$xs]<br>
<br>
<br>
<br>
Here's my try for timing:<br>
<br>
*Main> (foldl1 (\x y -> f y) .concat.replicate 1000000 $ unfoldr
(knip 6) an)<br>
"UVWXYZ7"<br>
(1.31 secs, 330291000 bytes)<br>
<br>
(It's incl. the construction of the test list, as is in the language to
compare )<br>
<br>
I need the whole list to be evaluated.<br>
Interpreted mode IS A MUST <span class="moz-smiley-s1"><span> :-) </span></span><br>
<br>
BTW I increased stack size<br>
<br>
<br>
thanks<br>
<br>
</tt><br>
Don Stewart schreef:
<blockquote cite="mid:20080803173209.GA10149@scytale.galois.com"
type="cite">
<pre wrap="">bradypus:
</pre>
<blockquote type="cite">
<pre wrap="">Suppose I've:
f = map g
I want to know how much time it takes (interpreted mode) to fully
process list xs (at least 1e6 elements) with function g. Is it
sufficient to execute:
*Main> last . f $ xs
<result>
(x.xx secs, yyyyyyyyyyy bytes)
Are there any hidden difficulties involved?
Reason is: comparing timings Haskell vs an interpreted language without
laziness.
</pre>
</blockquote>
<pre wrap=""><!---->
If you care about timings, it's probably a better idea to compile the
code (with optimisations on), to get a better idea of what the code
would do in a production environment.
You could then just time the binary,
main = print . sum $ ....
ghc -O2 A.hs --make
time ./A
-- Don
</pre>
</blockquote>
</body>
</html>