[Haskell-cafe] Associative array updating

[Cale Gibbard]

Hello again,

Actually ran the original code (on the same file, still using
gnome-terminal). I noticed that it sped up as it went along, so it
didn't actually take quite as much time as I originally thought it
might.
real   13m5.190s
user    6m1.595s
sys     0m3.061s

By the way, the finitemap code, when run from the linux console, as
opposed to a gnome-terminal gives 5.189s of real time. (The disparity
between real and user times really was gnome-terminal's fault).

 - Cale

On Mon, 3 Jan 2005 03:06:28 -0500, Cale Gibbard <cgibbard at gmail.com> wrote:
> Hello,
> 
> I found the following implementation using finite maps to work rather
> well. (See http://www.haskell.org/ghc/docs/latest/html/libraries/base/Data.FiniteMap.html)
> -------------------
> import Char
> import Data.FiniteMap
> 
> isLetter c = isAlphaNum c || c=='\''
> 
> normalize = map toLower . filter isLetter
> 
> nwords = filter (not . null) . map normalize . words
> 
> wordCount w = addListToFM_C (+) emptyFM (zip (nwords w) [1,1 ..])
> 
> main = do
>     s <- getContents
>     mapM_ print $ fmToList $ wordCount s
> -----------------
> 
> On a file with 264724 words and 17391 distinct words, this had the
> following times:
> real    0m38.208s
> user    0m4.302s
> sys     0m0.214s
> 
> It was compiled with -O using ghc 6.2.2. I had to increase the stack
> size slightly with a commandline option.
> 
> Most of the time was actually spent rendering the output. I didn't
> bother to wait for the original code to finish, as it was reporting
> only a few distinct words per second.
> 
> Hope this helps
>  - Cale