Bright Sun wrote:
> I can not understand memoization in Haskell. I can
> not find an example except the fib.
>
> For example, I want drop a list 4 times like,
>
> >drop 4 (drop 3 (drop 2 (drop 1
> [1,2,3,4,5,6,7,8,9,10,11,12])))
> >[11,12]
>
> can I implement a memoization funcation like
>
> >droploop [1,2,3,4] [1,2,3,4,5,6,7,8,9,10,11,12]
> to get same result
> >[11,12]
That isn't memoization.
Memoization is where you record a set of prior argument/result pairs
(i.e. a lookup table) to avoid having to perform the exact same
calculation repeatedly.
You can implement droploop as a fold, e.g.:
droploop ns xs = foldr drop xs ns
--
Glynn Clements <[EMAIL PROTECTED]>
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