When calling an F# async workflow, can I avoid defining a temporary label?

Question

Suppose I have an async data source:

let getData() = async { return [ 3.14; 2.72 ] }

I could call it using let! and a temporary label:

let showData1() = async {
    let! data = getData()
    data
    |> Seq.iter (printfn "%A")
}

Or, I could call it (inefficiently!) using Async.RunSynchronously and piping, and without a temporary label:

let showData2() = async {
    getData()
    |> Async.RunSynchronously
    |> Seq.iter (printfn "%A")
}

I like the syntax of showData2 but know that calling Async.RunSynchronously ties up the calling thread.

Is there a syntax, operator, or function defined somewhere that allows me to pipe an Async<'T> into a function that accepts 'T?

Answer 1

It sounds like you want map for Async:

let mapAsync f a = async { 
    let! v = a
    return (f v)
}

then you can do:

let m: Async<unit> = getData() |> mapAsync (Seq.iter (printfn "%A"))