Re: [Haskell-beginners] How memorize intermediate computation value[my brain is so hurt]?

There are quite a few packages on hackage that do memoization. Many of them actually have fibonacci sequences as examples. These vary in terms of complexity. http://hackage.haskell.org/package/data-memocombinators http://hackage.haskell.org/package/monad-memo http://hackage.haskell.org/package/memoize On Sat, Feb 4, 2012 at 5:36 AM, anyzhen wrote:

there have a lot of situation we need memorize intermediate computation value. and use in further. like this, compute nth fib question. So,how memorize it?

i have an ugly solution.it used HashTable for memorization.

fib n table  | n==1 =1  | n==2 =1  | otherwise =   case lookup table of     Just v   ->(v,table)     Nothing ->let (v,table') = fib (n-1) table in                    let ( v',table'')= v + fib(n-2) table' in                    (v',table'')

i am an beginner come from imperative programming language. so fib memorize version program hurt my brain ... particular in Nothing branches. so do you have some good idea

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