| C | |
| Comparable [Utils] | 
Interface for comparable and hashable types.
 | 
| S | |
| S [Printer] | 
Generic signature of a printer-parser.
 | 
| S [Calendar_sig] | 
Common operations for all calendar representations.
 | 
| S [Date_sig] | 
Common operations for all date representations.
 | 
| S [Time_sig] | 
Common operations for all time representations.
 | 
| S [Period] | 
Common interface for all periods.
 | 
| Second [Time_sig] | 
Interface for seconds.
 |