[clean-list] Clean versus Haskell

[Philippos Apolinarius]

I wrote a very simple program to check whether Haskell improved its array processing libraries or not. Here is how to compile and run the program arr.hs in Haskell (I have used the GHC compiler):

>ghc -O arr.hs -o arr.exe

$ time arr.exe +RTS -K32000000
2.8e8

real    0m3.938s
user    0m0.031s
sys     0m0.000s

The same program in Clean:
C:\Clean 2.2\exemplos\console>arraytest.exe
280000000
Execution: 0.01  Garbage collection: 0.01  Total: 0.03

C:\Clean 2.2\exemplos\console>arraytest.exe
280000000
Execution: 0.01  Garbage collection: 0.01  Total: 0.03

This means that Clean is 390 times faster than Haskell in this particular problem. These results makes me worder whether Haskell is safer than Clean. It turns out that Haskell checks index out of range at runtime, exactly like Clean. Larger problems make the difference between Clean and Haskell even worse. For instance, neural networks like the one described in Schmidtt et al. run 400 times faster in Clean.

Haskell seems to be slow, and not safe. For instance, GHC compiler does not at a program trying to write into a closed handle. 

module Main where
 import System( getArgs )
 import IO

 main = do 
          args <- getArgs
          if (length args /= 2)
        then putStr "Usage: f1a f2a <n>"
            else (do
              fromHandle <- openFile (head args)  ReadMode
              contents   <- hGetContents fromHandle
              toHandle <- openFile (head (tail args)) WriteMode
              hClose toHandle  -- Comment this line
              hPutStr toHandle contents
              hClose toHandle
              putStr "Done.")

The Clean equivalent program is somewhat smaller. In my opinion it is easier to understand. What is more important, Clean compiler balks at closed handles.

module cleancopy
import StdEnv, ArgEnv

Start w
  # argv= getCommandLine
  | size argv < 3 = abort "Usage, etc." 
  # (ok, f, w)= fopen argv.[1] FReadText w
      (contents, f)= freads f 64000
      (ok, f, w)= fopen argv.[2] FWriteText w
      f= fwrites contents f
  = fclose f w

Below you will find the array examples. You can check that Clean is really much faster than Haskell. I wonder why the Benchmarks Game site does not report such a large difference between Haskell and Clean performances. I believe that people who wrote Haskell benchmarks for the Benchmarks Game site cheated in using foreign pointers to access arrays.

-- arr.hs
import Control.Monad.ST
import Data.Array.ST
main = print $ runST
          (do arr <- newArray (1,2000000) 
                        137.0 :: ST s 
                                  (STArray s 
                                    Int Double)
              a <- readArray arr 1
              b <- readArray arr 1
              fn 2000000 arr 0.0 )


fn i a acc | i < 1 = do (return acc) 
fn i a acc= do 
             b <- readArray a i
             writeArray a i (b+3.0)
             c <- readArray a i
             fn (i-1) a (acc+c)

//Clean version
module arraytest
import StdEnv
fn i a acc | i<1 = acc
fn i a=:{[i]=b} acc
  # a= {a&[i]= b+3.0}
  # (c, a)= a![i]
  = fn (i-1) a (c+acc)
  
Start= fn 2000000 vt 0.0
where
   vt:: .{#Real}
   vt = createArray 2000001 137.0



--- On Mon, 10/12/09, rinus plasmeijer <rinus at cs.ru.nl> wrote:

From: rinus plasmeijer <rinus at cs.ru.nl>
Subject: [clean-list] Re: Clean
To: "Henrique" <henrique_gusmao_ at hotmail.com>
Cc: clean-list at science.ru.nl
Received: Monday, October 12, 2009, 1:22 AM



 
 


Hi Henrique

 
> Is this e-mail still working? http://clean.cs.ru.nl/
 
 
Yes.

 
>I want to know more about Clean: news? 
updates?
> What is the future of Clean?
 
See: http://wiki.clean.cs.ru.nl/Latest_developments
We are working on a new version which allows you to 
mix Clean and Haskell 98 code.
It is a lot of work, it will still take some time. 
 
> Is Haskell killing Clean? 
Haskell is certainly much more used, which is also 
the raison for adding a Haskell front end.

> I would like to 
learn and test Clean, and maybe then use it commercially. 
> Where do I 
can download it? I send e-mail to clean at cs.ru.nl , asked for 
Clean at the site above, but I got no answer.

We did not got your 
email.
To download browse to: http://clean.cs.ru.nl/Download/main/main.htm
 
> Obs: I am using windows platform. 
Thats fine, it should work on any windows platform.
 

Greetings,
 
Rinus
 
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