Merge pull request #1386 from eiriktsarpalis/csharp-optional-param-compat

[WIP] Implement implicit converter for F# optionals

Author: KevinRansom

src/fsharp/FSharp.Core.Unittests/SurfaceArea.net20.fs

@@ -1977,6 +1977,7 @@ Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1+Ta
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] None
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] Some(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] get_None()
+Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] op_Implicit(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.String ToString()
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpOption`1[T]: T Value

src/fsharp/FSharp.Core.Unittests/SurfaceArea.net40.fs

@@ -2138,6 +2138,7 @@ Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1+Ta
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] None
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] Some(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] get_None()
+Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] op_Implicit(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.String ToString()
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpOption`1[T]: T Value

src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable259.fs

@@ -2114,6 +2114,7 @@ Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1+Ta
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] None
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] Some(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] get_None()
+Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] op_Implicit(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.String ToString()
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpOption`1[T]: T Value

src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable47.fs

@@ -2111,6 +2111,7 @@ Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1+Ta
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] None
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] Some(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] get_None()
+Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] op_Implicit(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.String ToString()
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpOption`1[T]: T Value

src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable7.fs

@@ -2127,6 +2127,7 @@ Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1+Ta
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] None
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] Some(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] get_None()
+Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] op_Implicit(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.String ToString()
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpOption`1[T]: T Value

src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable78.fs

@@ -2114,6 +2114,7 @@ Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1+Ta
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] None
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] Some(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] get_None()
+Microsoft.FSharp.Core.FSharpOption`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] op_Implicit(T)
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.String ToString()
 Microsoft.FSharp.Core.FSharpOption`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpOption`1[T]: T Value

src/fsharp/FSharp.Core/prim-types.fs

@@ -3462,6 +3462,8 @@ namespace Microsoft.FSharp.Core
 
         static member Some(x) : 'T option = Some(x)
 
+        static member op_Implicit(x) : 'T option = Some(x)
+
         override x.ToString() = 
            // x is non-null, hence Some
            "Some("^anyToStringShowingNull x.Value^")"

src/fsharp/FSharp.Core/prim-types.fsi

@@ -1740,6 +1740,11 @@ namespace Microsoft.FSharp.Core
         /// <returns>An option representing the value.</returns>
         static member Some : value:'T -> 'T option
 
+        /// <summary>Implicitly converts a value into an optional that is a 'Some' value.</summary>
+        /// <param name="value">The input value</param>
+        /// <returns>An option representing the value.</returns>
+        static member op_Implicit : value:'T -> 'T option
+
         [<CompilationRepresentation(CompilationRepresentationFlags.Instance)>]
         /// <summary>Get the value of a 'Some' option. A NullReferenceException is raised if the option is 'None'.</summary>
         member Value : 'T

tests/fsharp/core/fsfromfsviacs/lib.fs

@@ -42,7 +42,15 @@ let tup3 = (2,3,4)
 let tup4 = (2,3,4,5)
 
 
+type OptionalParameterTests =
+    static member MethodWithOptionalParams<'T>(?value1 : 'T, ?value2 : int) = (value1, value2)
 
+    static member FSharpMethodThatConsumesOptionalParams() = 
+        let _ = OptionalParameterTests.MethodWithOptionalParams<int>()
+        let _ = OptionalParameterTests.MethodWithOptionalParams<int>(42)
+        let _ = OptionalParameterTests.MethodWithOptionalParams<int>(value2 = 42)
+        let _ = OptionalParameterTests.MethodWithOptionalParams<int>(42, ?value2 = None)
+        ()
 
 
 module StructUnionsTests =
@@ -111,6 +119,4 @@ module NestedStructUnionsTests =
     let testPattern3mut(u2:U2) = 
         let mutable u2 = u2
         match u2 with
-        | U2(U1(dt1,"a"),U1(dt2,"b")) -> (dt1 = dt2) 
-
-
+        | U2(U1(dt1,"a"),U1(dt2,"b")) -> (dt1 = dt2) 

tests/fsharp/core/fsfromfsviacs/lib2.cs

@@ -1,3 +1,4 @@
+using System;
 using Microsoft.FSharp;
 using Microsoft.FSharp.Core;
 using Microsoft.FSharp.Collections;
@@ -60,3 +61,20 @@ public static void SomeMethod() { }
 
     }
 }
+
+namespace FSharpOptionalTests
+{
+    public class ApiWrapper 
+    {
+        public static Tuple<FSharpOption<T>, FSharpOption<int>> MethodWithOptionalParams<T>(T value1, int value2)
+        {
+            return Lib.OptionalParameterTests.MethodWithOptionalParams<T>(value1 = value1, value2 = value2);
+        }
+
+        public static int MethodThatImplicitlyConvertsFSharpOption(int x)
+        {
+            FSharpOption<int> opt = x;
+            return opt.Value;
+        }
+    }
+}