Matrix and Vector implement interfaces

src/FSharpPlus.TypeLevel/Data/Matrix.fs

@@ -16,7 +16,7 @@ type Matrix< 'Item, 'Row, 'Column > = private { Items: 'Item[,] } with
   [<MethodImpl(MethodImplOptions.AggressiveInlining)>]
   static member UnsafeCreate (_row: 'm, _column: 'n, items: _[,]) : Matrix<_, 'm, 'n> =
     { Items = items }
-  (*
+
   interface System.Collections.Generic.IReadOnlyCollection<'Item> with
     member this.Count = this.Items.Length
     member this.GetEnumerator() = this.Items.GetEnumerator()
@@ -27,7 +27,7 @@ type Matrix< 'Item, 'Row, 'Column > = private { Items: 'Item[,] } with
           for j = 0 to (items |> Array2D.length2) - 1 do
             yield items.[i,j]
       }).GetEnumerator()
-  *)
+
 
 [<Struct; StructuredFormatDisplayAttribute("{Items}")>]
 type Vector<'Item, 'Length> = private { Items: 'Item[] } with
@@ -36,13 +36,13 @@ type Vector<'Item, 'Length> = private { Items: 'Item[] } with
   [<MethodImpl(MethodImplOptions.AggressiveInlining)>]
   static member UnsafeCreate (_length: 'n, items: _[]) : Vector<_, 'n> =
     { Items = items }
-  (*
+
   interface System.Collections.Generic.IReadOnlyList<'Item> with
     member this.Count = this.Items.Length
     member this.Item with get i = this.Items.[i]
     member this.GetEnumerator() = this.Items.GetEnumerator()
     member this.GetEnumerator() = (this.Items :> seq<_>).GetEnumerator()
-  *)
+
 
 module Vector =
   [<MethodImpl(MethodImplOptions.AggressiveInlining)>]

tests/FSharpPlus.Tests/TypeLevel.fs

@@ -206,3 +206,23 @@ module TypeProviderTests =
         Assert (Matrix.colLength row1 =^ (Z |> S |> S |> S))
         areEqual 5 (Matrix.get Z (S Z) row1)
         areEqual [3; 6; 9] (Vector.toList col2)
+
+module TestFunctors1 =
+    [<Test>]
+    let applicativeOperatorWorks() =
+        let v = vector ((fun i -> i + 1), (fun i -> i * 2))
+        let u = vector (2, 3)
+        let vu = v <*> u
+        NUnit.Framework.Assert.IsInstanceOf<Option<Vector<int,S<S<Z>>>>> (Some vu)
+        CollectionAssert.AreEqual ([|3; 6|], Vector.toArray vu)
+
+module TestFunctors2 =
+    open FSharpPlus
+
+    [<Test>]
+    let applicativeWorksWithoutSubsumption() =
+        let v = vector ((fun i -> i + 1), (fun i -> i * 2))
+        let u = vector (2, 3)
+        let vu = v <*> u
+        NUnit.Framework.Assert.IsInstanceOf<Option<Vector<int,S<S<Z>>>>> (Some vu)
+        CollectionAssert.AreEqual ([|3; 6|], Vector.toArray vu)