Offset Indexing and Slicing


In effect, it would be really nice to be able to mix an OffsetBound with an Index in some kind of range expression. But doing so may require re-thinking everything from Swift's subscript syntax to new hierarchies of range expressions. This sorta blew open the investigation area to a degree where I was unable to make progress at that time, and it could be a while before I can re-visit this.