The vertical bar indicates the Current Token Index.

Check current token for PreDirectional.
  If the token appears to be a PreDirectional.
    a. If there is not at least one available value after the directional
       and before the first post-street value, then the current token must be
       the street name.
                   |
       Before: 123 North Street
     
       Do not use the current token as a PreDirectional.
     
       The PreDirectional Parsing ends.

    b. If there is at least one available value after the directional and before
       the first post-street value, then the current token is not the street name.
                   |
       Before: 123 North East Main Street

       Set the PreDirectional property to the current token and increment the
       current token index.

       PreDirectional = "N".
                        |
       After: 123 North East Main Street

       Check for Multi-word PreDirectional.

         If the preceding directional is "N" or "S" and the current directional
         is "E" or "W".

           If there is at least one available value including the directional and
           before the first post-street value.
                               |
             Before: 123 North East Main Street
       
             Create the two character PreDirectional and increment the current
             token index.

             PreDirectional = "NE".
                                   |
             After: 123 North East Main Street