[Haskell-cafe] Re: String vs ByteString

[Daniel Fischer]

Hi Bulat,

On Monday 16 August 2010 07:35:44, Bulat Ziganshin wrote:
> Hello Daniel,
>
> Sunday, August 15, 2010, 10:39:24 PM, you wrote:
> > That's great. If that performance difference is a show stopper, one
> > shouldn't go higher-level than C anyway :)
>
> *all* speed measurements that find Haskell is as fast as C, was
> broken.

That's a pretty bold claim, considering that you probably don't know all 
such measurements ;)

But let's get serious. Bryan posted measurements showing the text (HEAD) 
package's performance within a reasonable factor of wc's. (Okay, he didn't 
give a complete description of his test, so we can only assume that all 
participants did the same job. I'm bold enough to assume that.)
Lazy text being 7% slower than wc, strict 30%.

If you are claiming that his test was flawed (and since the numbers clearly 
showed Haskell slower thanC, just not much, I suspect you do, otherwise I 
don't see the point of your post), could you please elaborate why you think 
it's flawed?

> Let's see:
>
> D:\testing>read MsOffice.arc
> MsOffice.arc 317mb -- Done
> Time 0.407021 seconds (timer accuracy 0.000000 seconds)
> Speed 779.505632 mbytes/sec

I see nothing here, not knowing what `read' is. None of read (n), read (2), 
read (1p), read(3p) makes sense here, so it must be something else.
Since it outputs a size in bytes, I doubt that it actually counts 
characters, like wc -m and, presumably, the text programmes Bryan 
benchmarked.
Just counting bytes, wc and Data.ByteString[.Lazy] can do much faster than 
counting characters too.