1 -- | This module defines the 'Configuration' type, which is just a
2 -- wrapper around all of the configuration options we accept on the
11 import System.Console.CmdArgs.Default ( Default(..) )
12 import System.Log ( Priority( INFO ) )
15 import Backend ( Backend(..) )
16 import ConnectionString ( ConnectionString )
17 import qualified OptionalConfiguration as OC (
18 OptionalConfiguration(..),
22 -- | The main configuration data type. It contains all options that
23 -- can be set in a config file or on the command line.
28 connection_string :: ConnectionString,
29 log_file :: Maybe FilePath,
30 log_level :: Priority,
35 -- | A Configuration with all of its fields set to their default
37 instance Default Configuration where
40 connection_string = def,
47 -- | Merge a Configuration with an OptionalConfiguration. This is more
48 -- or less the Monoid instance for 'OptionalConfiguration', but since
49 -- the two types are different, we have to repeat ourselves.
51 merge_optional :: Configuration
52 -> OC.OptionalConfiguration
54 merge_optional cfg opt_cfg =
56 (merge (backend cfg) (OC.backend opt_cfg))
57 (merge (connection_string cfg) (OC.connection_string opt_cfg))
58 (OC.merge_maybes (log_file cfg) (OC.log_file opt_cfg))
59 (merge (log_level cfg) (OC.log_level opt_cfg))
60 (merge (remove cfg) (OC.remove opt_cfg))
61 (merge (syslog cfg) (OC.syslog opt_cfg))
63 -- | If the thing on the right is Just something, return that
64 -- something, otherwise return the thing on the left.
65 merge :: a -> Maybe a -> a