Initial data commit

Task/Currying/Visual-Basic-.NET/currying-3.vb

@@ -0,0 +1,51 @@
+Option Explicit On
+Option Infer On
+Option Strict On
+
+Module CurryingDynamic
+    ' Cheat visual basic's syntax by defining a type that can be the receiver of what appears to be a method call.
+    ' Needless to say, this is not idiomatic VB.
+    Class CurryDelegate
+        ReadOnly Property Value As Object
+        ReadOnly Property Target As [Delegate]
+
+        Sub New(value As Object)
+            Dim curry = TryCast(value, CurryDelegate)
+            If curry IsNot Nothing Then
+                Me.Value = curry.Value
+                Me.Target = curry.Target
+            ElseIf TypeOf value Is [Delegate] Then
+                Me.Target = DirectCast(value, [Delegate])
+            Else
+                Me.Value = value
+            End If
+        End Sub
+
+        ' CurryDelegate could also work as a dynamic n-ary function delegate, if an additional ParamArray argument were to be added.
+        Default ReadOnly Property Invoke(arg As Object) As CurryDelegate
+            Get
+                If Me.Target Is Nothing Then Throw New InvalidOperationException("All curried parameters have already been supplied")
+
+                Return New CurryDelegate(Me.Target.DynamicInvoke({arg}))
+            End Get
+        End Property
+
+        ' A syntactically natural way to assert that the currying is complete and that the result is of the specified type.
+        Function Unwrap(Of T)() As T
+            If Me.Target IsNot Nothing Then Throw New InvalidOperationException("Some curried parameters have not yet been supplied.")
+            Return DirectCast(Me.Value, T)
+        End Function
+    End Class
+
+    Function DynamicCurry(func As [Delegate]) As CurryDelegate
+        Return DynamicCurry(func, ImmutableList(Of Object).Empty)
+    End Function
+
+    ' Use ImmutableList to create a new list every time any curried subfunction is called avoiding multiple or repeated
+    ' calls interfering with each other.
+    Private Function DynamicCurry(func As [Delegate], collectedArgs As ImmutableList(Of Object)) As CurryDelegate
+        Return If(collectedArgs.Count = func.Method.GetParameters().Length,
+            New CurryDelegate(func.DynamicInvoke(collectedArgs.ToArray())),
+            New CurryDelegate(Function(arg As Object) DynamicCurry(func, collectedArgs.Add(arg))))
+    End Function
+End Module