A Calculation Engine for .NET

Friend Class Logical

    ' Methods
    Public Shared Sub Register(ByVal ce As CalcEngine)
        ce.RegisterFunction("AND", 1, Integer.MaxValue, New CalcEngineFunction(AddressOf Logical.And))
        ce.RegisterFunction("OR", 1, Integer.MaxValue, New CalcEngineFunction(AddressOf Logical.Or))
        ce.RegisterFunction("NOT", 1, New CalcEngineFunction(AddressOf Logical.Not))
        ce.RegisterFunction("IF", 3, New CalcEngineFunction(AddressOf Logical.If))
        ce.RegisterFunction("TRUE", 0, New CalcEngineFunction(AddressOf Logical.True))
        ce.RegisterFunction("FALSE", 0, New CalcEngineFunction(AddressOf Logical.False))
    End Sub

    Private Shared Function [And](ByVal p As List(Of Expression)) As Object
        Dim b As Boolean = True
        Dim v As Expression
        For Each v In p
            b = (b AndAlso CBool(v))
        Next
        Return b
    End Function

    Private Shared Function [False](ByVal p As List(Of Expression)) As Object
        Return False
    End Function

    Private Shared Function [If](ByVal p As List(Of Expression)) As Object
        If p.Item(0) Is Nothing Then
            Return p.Item(2).Evaluate
        Else
            If CBool(p.Item(0)) Then
                Return p.Item(1).Evaluate
            Else
                Return p.Item(2).Evaluate
            End If
        End If
    End Function

    Private Shared Function [Not](ByVal p As List(Of Expression)) As Object
        Return Not CBool(p.Item(0))
    End Function

    Private Shared Function [Or](ByVal p As List(Of Expression)) As Object
        Dim b As Boolean = False
        Dim v As Expression
        For Each v In p
            b = (b OrElse CBool(v))
        Next
        Return b
    End Function

    Private Shared Function [True](ByVal p As List(Of Expression)) As Object
        Return True
    End Function

End Class