Performance Logger - Computational Expression that logs how long a function ran

performanceLogger.fs

open System.Diagnostics
open System.Threading
type PerformanceLogger (printer:string -> unit) =
    member this.Bind(x, func) = 
        let stopWatch = new Stopwatch()
        stopWatch.Start ()
        func x
        stopWatch.Stop ()
        printer (sprintf "Took %i seconds to run %A" (stopWatch.ElapsedMilliseconds/1000L) (func))

    member this.Zero () = ()

    member this.Return x = x