The help file for grid.line.to says that Grid has the notion of a current location. Is there a way to get that current location? I looked for a function that returns this but I didn't find anything. Basically, I'm looking to do something like turtle graphics and I need to write a function like grid.line.to but where the endpoint is defined relative to the current location (i.e. grid.line.to.rel(-1,0) would draw a unit line left from the current location).