Question

module BirthdayLibrary = 
    type Birthday =
        { day   :int
          month :int }

module DataGen = 
    let birthdayGenerator (months:option<list<int>>) = 
        let monthGen = match months with
                       | Some m -> Gen.elements m
                       | None   -> FsCheck.Gen.choose(1,12)
        (fun m d -> { day   = d
                      month = m}:BirthdayLibrary.Birthday)
        <!> monthGen
        <*> FsCheck.Gen.choose(1,28)

    //I want this to have the signature Gen<BirthdayLibrary.Birthday list>
    let oneForEveryMonthGen = 
        [ for m in [1 .. 12] ->
            (fun mo -> birthdayGenerator (Some [mo]))]

让我说我有类似上面的东西。我有一个返回类型为Gen＆lt; BirthdayLibrary.Birthday＆gt;的生日生成器。您可以选择指定月份。来自Gen＆lt; a＆gt;的最佳方式是什么？到Gen＆lt; a list＆gt;何时为列表中的项目指定一些约束？我可以想办法获得＆lt; Gen＆lt; a＆gt; list＆gt;，我认为它不适用于编写应包含＆lt; list a＆gt;的父对象。（这是这个例子的基础）。我也可以想办法做Gen＆lt; Gen＆lt; a＆gt; list＆gt;，我有组合问题以及列表中的所有值都是相同的。我看过Gen.arrayOf，我无法想到如何使用数组中每个项目的值。

Answer 1

module BirthdayLibrary = 
    type Birthday =
        { day   :int
          month :int }

module DataGen = 
    let birthdayGenerator (months:option<list<int>>) = 
        let monthGen = match months with
                       | Some m -> Gen.elements m
                       | None   -> FsCheck.Gen.choose(1,12)
        (fun m d -> { day   = d
                      month = m}:BirthdayLibrary.Birthday)
        <!> monthGen
        <*> FsCheck.Gen.choose(1,28)

    //I want this to have the signature Gen<BirthdayLibrary.Birthday list>
    let oneForEveryMonthGen = 
        [ for m in [1 .. 12] -> birthdayGenerator (Some [m])]
        |> Gen.sequence

let sample = DataGen.oneForEveryMonthGen |> Gen.sample 10 1

给了我：

val sample：BirthdayLibrary.Birthday list list = [[{day = 7; month = 1;}; {day = 15; month = 2;}; {day = 13; month = 3;}; {day = 14; 月= 4;}; {day = 28; 月= 5;}; {day = 9; 月= 6;}; {day = 28; 月= 7;}; {day = 15; 月= 8;}; {day = 6; 月= 9;}; {day = 21; 月= 10;}; {day = 12; 月= 11;}; {day = 27; 月= 12;}]]

有没有办法从Gen <a> to Gen</a> <a list=""> while specifying a bound?</a>开始

1 个答案: