microsoft-visualbasic-runtime/Language/Linq/Rapply.vb

34 lines
1.1 KiB
VB.net

Imports System.Reflection
Imports System.Runtime.CompilerServices
Imports Microsoft.VisualBasic.ComponentModel.Collection.Generic
Namespace Language
''' <summary>
''' Helper for implements ``lapply`` and ``sapply`` liked operations from R language
''' </summary>
Public Module Rapply
<Extension>
Public Function lapply(Of Tin As INamedValue, TOut)(sequence As IEnumerable(Of Tin), apply As [Delegate], ParamArray args As Object()) As Dictionary(Of String, TOut)
Dim result As New Dictionary(Of String, TOut)
Dim key$
Dim value As Object
Dim arguments As Object() = New Object(args.Length) {}
Dim method As MethodInfo = apply.Method
Dim obj As Object = apply.Target
Call Array.ConstrainedCopy(args, Scan0, arguments, 1, args.Length)
For Each item As Tin In sequence
key = item.Key
arguments(Scan0) = item
value = method.Invoke(obj, arguments)
result.Add(key, value)
Next
Return result
End Function
End Module
End Namespace