@hackage array-memoize0.6.0

Memoization combinators are great for providing high-performance Haskell programs, but they can be even faster if memoization is performed on a finite, discrete domain since an array can then be used to store results.

This package provides various combinators for doing just this, including also combinators for quanitzing and discretizing Float/Double-valued functions.

Example:

fib' :: (Int -> Int) -> Int -> Int
fib' _ 0 = 1
fib' _ 1 = 1
fib' rec n = rec (n - 1) + rec (n - 2)
fib :: Int -> Int
fib = arrayMemoFix (0, 1000) fib'