Memoization isn't a new thing. It's available in Haskell as a first class citizen.
This benchmark explicitly targets popular languages, and it happens to include no pure functional languages.
This benchmark explicitly targets popular languages, and it happens to include no pure functional languages.
Not really. Haskell's laziness makes it easier to write functions that are memoized, but it does not automagically memoize functions. And how could it without incurring a non-trivial runtime space/time cost?
Haskell's purity is what makes it easier to write libraries that facilitate building memoized versions of functions in a transparent way (and that are obviously correct). For instance, I usually reach for [data-memocombinators][0], which happens to have a fibonacci example at the top of the docs:
import qualified Data.MemoCombinators as Memo
fib = Memo.integral fib'
where
fib' 0 = 0
fib' 1 = 1
fib' x = fib (x-1) + fib (x-2)
[0]: http://hackage.haskell.org/package/data-memocombinators-0.5.1/docs/Data-MemoCombinators.html