Nothing settles a debate like cold, hard facts. If you wrote a function that you think is the fastest algorithm possible, the only way to know for sure is to test it. Elm-Benchmark looks similar to Elm-Test, but instead of checking for correctness, it checks for speed.
module Main exposing (..)
import Benchmark exposing (Benchmark, describe)
import Benchmark.Runner exposing (BenchmarkProgram, program)
import Model exposing (..)
suite : Benchmark
[ Benchmark.compare "shufflers"
(Benchmark.benchmark1 "array" shuffledDeck 0)
(Benchmark.benchmark1 "naive" naiveShuffledDeck 0)
main : BenchmarkProgram