Use panic for exception handling, much cleaner.
Handle long values with panic/recover.
Formatting.
Rename RangeState to State, no need to double prefix.
Re-export mapset.Set as grange.Result
Tidy up and documentation of public interface.
Make RangeQuery package private.
Make parser function package private.
Parser nodes to package private.
Rename Node to parserNode.
Make parser package private.
Documentation.