Bulat Ziganshin wrote:
i've improved memory usage of my program 3 times one month after i've started to use Haskell, and 4 times more 1.5 years later (the last improvement included development of ByteString-alike library and strictifying some computations). i think that for programming-in-large experienced haskeller may reach C-like level of efficiency, unlike for programming-in-small (i.e. implementation of raw computations)
Yeah, I spent yesterday building a whole toolbox of compression algorithms. However, it turns out that just one algorithm - BWT - is too absurdly slow. You may recall I implemented that a while back, and discovered that making it use a lazy ByteString make it many orders of magnitude faster.
Trouble is... the whole of the rest of my toolbox uses normal lists. So I'm going to have to do some horribly ugly hack just to make BWT work properly. (Like, I've built this whole nice abstract framework for all the other algorithms, and I'm going to have to punch a massive hole through the middle of it to make a ByteString BWT fit.) It's a real shame. (OTOH, I waited over 5 minutes for my program to try to take the BWT of a 12 KB file. It used in excess of 2 GB of RAM. That's clearly absurd...)
Does anybody have any clue why ByteStrings are actually faster? (And why this information isn't easily findable anywhere - must shorly be a VFAQ.)
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