Array Extensions

[minitech]

Some useful Array/IEnumerable/etc. extensions. The "extension" part, of course, requires VS 2008 or higher. Enjoy!

Imports System.Runtime.CompilerServices

Public Module Extensions
    <Extension(), DebuggerStepThrough()> _
    Public Sub BitRotateLeft(ByVal arr() As Byte)
        If arr.Length = 0 Then Exit Sub

        Dim carry As Byte = arr(0) >> 7
        For i As Integer = arr.Length - 1 To 0 Step -1
            Dim newCarry As Integer = arr(i) >> 7
            arr(i) = arr(i) << 1 Or carry
            carry = newCarry
        Next
    End Sub

    <Extension(), DebuggerStepThrough()> _
    Public Sub BitRotateLeft(ByVal arr() As Byte, ByVal amount As Integer)
        For i As Integer = 1 To amount
            arr.BitRotateLeft()
        Next
    End Sub

    <Extension(), DebuggerStepThrough()> _
    Public Sub BitRotateRight(ByVal arr() As Byte, Optional ByVal amount As Integer = 1)
        arr.BitRotateLeft(32 - amount Mod 32)
    End Sub
End Module