原型的可枚举#拉入F#?

您可以使用类型扩展和反射来实现这一点。我们使用pull函数简单地扩展了泛型列表类型。然后,我们可以在任何列表中使用pull()。未知属性将返回仅包含错误字符串的列表。

type Microsoft.FSharp.Collections.List<'a> with
    member list.pluck property = 
        try 
            let prop = typeof<'a>.GetProperty property 
            [for elm in list -> prop.GetValue(elm, [| |])]
        with e-> 
            [box <| "Error: Property '" + property + "'" + 
                            " not found on type '" + typeof<'a>.Name + "'"]

let a = ["aqueous"; "strength"; "hated"; "sesquicentennial"; "area"]

a.pluck "Length" 
a.pluck "Unknown"

> a.pluck "Length" ;; 
val it : obj list = [7; 8; 5; 16; 4]

> a.pluck "Unknown";;
val it : obj list = ["Error: Property 'Unknown' not found on type 'String'"]

丹尼亚舍尔

> &燃气轮机; &燃气轮机;

注意:使用时 <pre &燃气轮机;周围的尖括号

<'a>

原型的 pluck object.method() 与 object[method] .

String.Length

#r "FSharp.PowerPack.dll" 
open Microsoft.FSharp.Compatibility
words |> List.map String.length 

http://research.microsoft.com/fsharp/manual/FSharp.PowerPack/Microsoft.FSharp.Compatibility.String.html

Compatibility 这可能会让查看代码的人更加困惑。