What are the best practices for benchmarking in Haskell?

What are the best practices for benchmarking in Haskell?

When benchmarking in Haskell, it's important to use the Criterion library for accurate results. It helps in measuring performance reliably.

How do I set up Criterion for my project?

To set up Criterion, add it to your project's dependencies in the cabal file or stack.yaml, then import it in your benchmarking module.

Can you give me an example of a simple benchmark?

Sure! Here's a simple benchmark:

import Criterion.Main

main :: IO ()
main = defaultMain [
    bgroup "my benchmarks" [
        bench "fib 20" $ whnf fib 20,
        bench "fib 30" $ whnf fib 30
    ]
]

fib :: Int -> Int
fib 0 = 0
fib 1 = 1
fib n = fib (n-1) + fib (n-2)

What should I avoid when benchmarking?

Avoid benchmarking in a non-isolated environment, as background processes can skew results. Also, don't forget to run benchmarks multiple times to get reliable averages.