Hi folks,
On Thu, 30 Sep 2004 01:02:54 +0100, Sam Mason <[EMAIL PROTECTED]> wrote:
Greg Buchholz wrote:
The algorithm isn't correct (it counts spaces instead of words), but
anyone have advice for improving its performance?
You probably want some strictness annotations in there. . .
<snip>
Last night as I have tried to improve Gregs wc in a simple fashion and came up with
the same idea to make a new data type with strict fields. I thought why one couldn't
add some kind of strictness annotation to the function type. First attempt:
wc :: !(Int,Int,Int) -> Char -> (Int, Int, Int)
As far as I know the compiler does strictness analysis to find strict arguments in a
function anyway. Would it make sense to allow this kind of explicit strictness? Where
are the problems with that?
I mean lazyness is really useful and it is our best friend in this kind of
application, since we can make stream processing without implementing a buffer and so
on. On the other hand one gets occasionally traped by it and it is not allways easy to
grasp why.
Some more general comment: The code for the shootout doesn't need to be extremly fast
in my eyes, it needs to be elegant and reasonable at performance and memory
consuptions (In this order). I don't want to say that Thomaszs solution is bad, but it
is not a typical Haskell style application. If someone (not haskeller) looks at the
implementation it should be very obvious and clear.
The last few weeks the list have been full of performance questions (including my own
ones) and it is really a pitty that it is such an issue. I believe that most problems
occuring with performance and memory consumptions could be easily solved by partial
and explicit strictness. Please enlight me if I am wrong.
Regards,
Georg
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