On Thursday, 24 May 2012 at 01:00:52 UTC, Jonathan M Davis wrote:
As part of my thesis work, I wrote a program which was counting
possible
tokens in code (as part of an AI attempting to learn about a
programming
language), which required a map of tokens to the number of
times that they'd
been seen. Because I had previously been doing stuff in Haskell
for my thesis,
I continued to use Haskell for that portion, and it was a
_huge_ mistake,
because the performance was _terrible_ - as in it could only
process a few
files in a day kind of terrible. I ultimately had to switch
over to another
language to get it to work (it ended up being Java, but I could
have used a
variety of other languages).
Maybe if I had simply been adding elements to the map, it
wouldn't have been
anywhere near as bad, but since I had to mutate them (and both
the map and its
elments were technically immutable), that become _insanely_
expensive.
So, it's quite possible that you have a use case where using
immutable
containers works really well and isn't a problem, but in what
I've dealt with
personally, I've found it to be a huge performance problem and
so am very
leery of immutable containers.
- Jonathan M Davis
Is source code available?
