[AdamSpeight2008]

From one my coding adventures.

The Offending Acts of Bodgery

• Use of Module
  Cos, I can't write base-class only methods.
  
• Use of reflection
  Unable to refer to static method on the Type specified by the Generic Type Parameter.
  VS suggest using Token.Parser which isn't the method in the derived type.

Public Module TokenModule
  Public Function Parse(Of T As Token)(cr As CharReader) As T
    '
    ' Here Be Nasty Reflection Based Bodge Job 
    '
    ' Why? What I want to write. ( Call a static method on the generic (constrianed) type specifier.)
    '
    ' Return T.Parser(cr)
    ' 
    ' Start Bodgery {
    Dim tt As T
    tt = GetType(T).InvokeMember("Parser",
                                    Reflection.BindingFlags.InvokeMethod +
                                    Reflection.BindingFlags.NonPublic +
                                    Reflection.BindingFlags.Static, Nothing, tt, {cr})
    Return tt
    ' } End Bodgery
  End Function

End Module

It would be so much nicer to write if it supported Partial Inheritance.

Spoiler

Public MustInherit Class Token
  Private _Index As Integer
  Private _Count As Integer
  Protected Friend Sub New(ByVal Index As Integer, Count As Integer)
    _Index = Index : _Count = Count
  End Sub
  Public ReadOnly Property Index As Integer
    Get
      Return _Index
    End Get
  End Property
  Public ReadOnly Property Count As Integer
    Get
      Return _Count
    End Get
  End Property
  ' Specify a shared method the derived class must implement.
  MustImplement Shared Function Parser(cr As CharReader) As Token

  ' Base-Class Only Method
  NotInheritable Public Shared Function Parse(Of T)(cr As CharReader) As T
   Return T.Parser(cr)
  End Function
End Class