.net - F# 函数在没有被调用的情况下运行

Question

这段代码

open System.Threading

let duration = 1000

module SequentialExample =
    let private someTask item =
        printfn "oh god why"
        Thread.Sleep(duration)
        item + " was computed"

    let private items = [
        "foo"
        "bar"
        "baz"
    ]

    let getComputedItems = 
        printfn "heh"
        [for item in items -> someTask item]
        |> Array.ofList

module ParallelExample =
    let private someTask item =
        printfn "that's ok"
        Thread.Sleep(duration)
        item + " was computed"

    let private items = [
        "foo"
        "bar"
        "baz"
    ]

    let getComputedItems = 
        Async.Parallel [for item in items -> async { return someTask item }]
        |> Async.RunSynchronously

[<EntryPoint>]
let main args =
    ParallelExample.getComputedItems |> ignore
    0

具有以下输出:

heh
oh god why
oh god why
oh god why
that's ok
that's ok
that's ok

如果我调用 ParallelExample模块，为什么 F# 运行 SequentialExample 中的代码模块？

我究竟做错了什么？

Answer 1

正如约翰帕尔默在评论中所说，let getComputedItems = ...实际上是一个值，而不是一个函数，因为函数必须接受参数 .

为了使它成为一个函数，必须像这样声明它let getComputedItems () = ... .