Extension points

tilttek/points

Point	What an application gives	Where
`Ledger\Ledger`	The storage of the ledger, in place of `InMemoryLedger`	Writing a ledger
`Psr\Clock\ClockInterface`	The clock that stamps each movement and decides expiry: the system's in production, a fixed one in tests	Testing

The currencies and the earning rules are values: Currencies::fromArray() and Rules::fromArray() read them from a configuration, or the application builds them in code. Every point is passed to the constructor of the service that uses it; the services keep no state of their own between two calls.