Class TStack

        Exported Instances:

        Exported Methods:

           Init()                 Constructor Method

           Push( cValue )         Adds an element into the stack

               cValue : value to add into the stack

           Pop()                  Extracts an element

           Len()                  Returns the length of the stack

           Empty()                Determines if the stack is empty

           Tail()                 Returns the highest element


        Function Demo()
        Local oStack := TStack():Init()
            oStack:Push( "Hello" )
            oStack:Len()                // 1
            oStack:Empty()              // .F.
            oStack:Tail()               // "Hello"
            ? oStack:Pop()              // "Hello"
            oStack:Empty()              // .T.
            oStack:Len()                // 0
        Return( Nil )