module type S =sig
..end
Common interface for all periods.
type +[< date_field ]
period
typet =
Period.date_field period
Type of a period.
val empty : [< date_field ] period
The empty period.
val add : ([< Period.date_field ] as 'a) period ->
'a period -> 'a period
Addition of periods.
val sub : ([< Period.date_field ] as 'a) period ->
'a period -> 'a period
Substraction of periods.
val opp : ([< Period.date_field ] as 'a) period -> 'a period
Opposite of a period.
val equal : [< date_field ] period -> [< date_field ] period -> bool
Equality function between two periods.
val compare : [< date_field ] period -> [< date_field ] period -> int
Comparison function between two periods.
val hash : [< date_field ] period -> int
Hash function for periods.