Am Samstag 28 November 2009 21:21:20 schrieb vishnu:
> this is where I've gotten to.
> http://moonpatio.com/fastcgi/hpaste.fcgi/view?id=5120#a5120
> strangely enough Ive gotten no speedup at all from the substitution cost
> UArray (though I had to make it Int, Int to deal with digits.).
Converting
vishnu wrote:
wow ok, I'm not even able to see why they're different in the desugared
version
They're different because case is strict binding (see caveat below)
whereas let is lazy binding. If we say,
let foo = big ugly computation in bar
Then if foo isn't used in bar, it'll never be c
vishnu wrote:
I always thought lazyness was automatic and
seq made strictness possible.
Laziness is the default, but that doesn't mean it's everywhere. For
example, every time you do pattern matching you enforce strictness:
foo (x:xs) = 5
==>
foo _|_ == _|_
However, there's also
this is where I've gotten to.
http://moonpatio.com/fastcgi/hpaste.fcgi/view?id=5120#a5120
strangely enough Ive gotten no speedup at all from the substitution cost
UArray (though I had to make it Int, Int to deal with digits.). But still I
wonder if there's something else I missed. Im really curious
On Fri, Nov 27, 2009 at 9:18 PM, vishnu wrote:
> Hi Bulat
> hmm ok I understand the issue of compiler maturity. But I thought
> lazyness was meant to be a bonus? Or is it that if you really try to squeeze
> performance it becomes more of a hindrance?
One of my favorite quotes by Heinrich Apfel
On Nov 27, 2009, at 23:18 , vishnu wrote:
hmm ok I understand the issue of compiler maturity. But I thought
lazyness was meant to be a bonus? Or is it that if you really try to
squeeze performance it becomes more of a hindrance?
If you're trying to eke out every last bit of performance,
Hi Bulat
hmm ok I understand the issue of compiler maturity. But I thought
lazyness was meant to be a bonus? Or is it that if you really try to squeeze
performance it becomes more of a hindrance?
On Sat, Nov 28, 2009 at 1:47 AM, Bulat Ziganshin
wrote:
> Hello Don,
>
> Friday, November 27, 2009,
Hi Daniel
Wow that's fantastic. Could you explain those further optimisations a bit
more please? Especially the whole "more lazyness" thing.
Timings here:
Your last ByteString code: 128s
That with corrected index calculation: 172s
Correct indices and distance orig new = f m n instead of memf m
wow I just woke up to see this :). Im impressed at the speed of the
response, thanks Daniel
Bad news first.
> a) According to codechef, you must also consider digits.
>
you're right, I totally missed this. Thanks :)
b) Your distance function is wrong.
>
> With idx i j = (i+1)*(j+1) - 1, you w
Am Samstag 28 November 2009 02:04:31 schrieb Daniel Fischer:
> Make it
>
> distance orig new = f m n
>
> and no thunks need be written at all in this case.
> Cuts down running time by nearly half :)
>
> I think you could speed it up significantly by calculating the distance
> more lazily.
Yup :D
Am Freitag 27 November 2009 20:41:37 schrieb vishnu:
> Ive just started learning haskell pretty recently and Ive been trying to
> solve some online contest problems as part of this exercise. However, Ive
> been having almost no success. For various reasons my answers almost always
> are too slow. I
Hello Don,
Friday, November 27, 2009, 11:08:44 PM, you wrote:
>> it's just false assumption that you should got speed comparable to
>> other languages. haskell is lazy and ghc has much less mature compiler
> "comparable to other languages" eh?
> That seems a little too broad to be meaningful, Bu
bulat.ziganshin:
> Hello vishnu,
>
> Friday, November 27, 2009, 10:41:37 PM, you wrote:
>
> it's just false assumption that you should got speed comparable to
> other languages. haskell is lazy and ghc has much less mature compiler
"comparable to other languages" eh?
That seems a little too bro
Hello vishnu,
Friday, November 27, 2009, 10:41:37 PM, you wrote:
it's just false assumption that you should got speed comparable to
other languages. haskell is lazy and ghc has much less mature compiler
> Ive just started learning haskell pretty recently and Ive been
> trying to solve some onli
Ive just started learning haskell pretty recently and Ive been trying to
solve some online contest problems as part of this exercise. However, Ive
been having almost no success. For various reasons my answers almost always
are too slow. I recently stumbled across this link which was quite useful
ht
15 matches
Mail list logo
