Of course, insisting on an immutable API that allows data sharing is going to produce different results than a mutable API. There exist mutable counterparts su

Of course, insisting on an immutable API that allows data sharing is going to produce different results than a mutable API. There exist mutable counterparts such as Data.Vector.Unboxed.Mutable and everything in the ST monad. The question is if you are allowing yourself to utilize them.