If you were to define some extension methods, properties in an assembly written in F#, and then use that assembly in C#, would you see the defined extensions in C#?
If so, that would be so cool.
[<System.Runtime.CompilerServices.Extension>]
module Methods =
[<System.Runtime.CompilerServices.Extension>]
let Exists(opt : string option) =
match opt with
| Some _ -> true
| None -> false
This method could be used in C# only by adding the namespace (using using) to the file where it will be used.
if (p2.Description.Exists()) { ...}
Here is a link to the original blogpost.
Answering question in comments "Extension Static Methods":
namespace ExtensionFSharp
module CollectionExtensions =
type System.Linq.Enumerable with
static member RangeChar(first:char, last:char) =
{first .. last}
In F# you call it like so:
open System.Linq
open ExtensionFSharp.CollectionExtensions
let rangeChar = Enumerable.RangeChar('a', 'z')
printfn "Contains %i items" rangeChar.CountItems
In C# you call it like so:
using System;
using System.Collections.Generic;
using ExtensionFSharp;
class Program
{
static void Main(string[] args)
{
var method = typeof (CollectionExtensions).GetMethod("Enumerable.RangeChar.2.static");
var rangeChar = (IEnumerable<char>) method.Invoke(null, new object[] {'a', 'z'});
foreach (var c in rangeChar)
{
Console.WriteLine(c);
}
}
}
Now, give me my freaking medal!
Despite my other answer, I did just try this with the F# CTP (on VS shell) and C# Express from my box at home (all free dev tools!), and this works:
F#
#light
namespace MyFSharp
// C# way
[<System.Runtime.CompilerServices.Extension>]
module ExtensionMethods =
[<System.Runtime.CompilerServices.Extension>]
let Great(s : System.String) = "Great"
// F# way
type System.String with
member this.Awesome() = "Awesome"
let example = "foo".Awesome()
C#
using System;
using MyFSharp; // reference the F# dll
class Program
{
static void Main(string[] args)
{
var s = "foo";
//s.Awesome(); // no
Console.WriteLine(s.Great()); // yes
}
}
I was not aware you could do this; nifty. Credit to @alex.