1 {-# LANGUAGE DeriveDataTypeable #-}
2 {-# LANGUAGE FlexibleInstances #-}
3 {-# LANGUAGE OverloadedStrings #-}
5 -- | The program will parse ~/.twatrc for any available configuration
6 -- directives, resulting in an OptionalCfg. The command-line
7 -- arguments will be used to create another OptionalCfg, and the two
8 -- will be merged. Finally, a default_config will be updated from
9 -- the merged OptionalCfgs.
12 module OptionalConfiguration (
18 import qualified Data.Configurator as DC
19 import qualified Data.Configurator.Types as DCT
20 import Data.Data (Data)
21 import Data.Maybe (fromMaybe)
22 import Data.Monoid (Monoid(..))
23 import Data.Typeable (Typeable)
25 -- | The same as Cfg, except everything is optional. It's easy to
26 -- merge two of these by simply dropping the Nothings in favor of
27 -- the Justs. The 'usernames' are left un-maybed so that cmdargs
28 -- can parse more than one of them.
31 OptionalCfg { consumer_key :: Maybe String,
32 consumer_secret :: Maybe String,
33 access_token :: Maybe String,
34 access_secret :: Maybe String,
35 heartbeat :: Maybe Int,
36 ignore_replies :: Maybe Bool,
37 ignore_retweets :: Maybe Bool,
38 sendmail_path :: Maybe String,
39 from_address :: Maybe String,
40 to_address :: Maybe String,
41 verbose :: Maybe Bool,
42 usernames :: [String] }
43 deriving (Show, Data, Typeable)
45 instance Monoid OptionalCfg where
62 (merge (consumer_key cfg1) (consumer_key cfg2))
63 (merge (consumer_secret cfg1) (consumer_secret cfg2))
64 (merge (access_token cfg1) (access_token cfg2))
65 (merge (access_secret cfg1) (access_secret cfg2))
66 (merge (heartbeat cfg1) (heartbeat cfg2))
67 (merge (ignore_replies cfg1) (ignore_replies cfg2))
68 (merge (ignore_retweets cfg1) (ignore_retweets cfg2))
69 (merge (sendmail_path cfg1) (sendmail_path cfg2))
70 (merge (from_address cfg1) (from_address cfg2))
71 (merge (to_address cfg1) (to_address cfg2))
72 (merge (verbose cfg1) (verbose cfg2))
75 merge :: (Maybe a) -> (Maybe a) -> (Maybe a)
76 merge Nothing Nothing = Nothing
77 merge (Just x) Nothing = Just x
78 merge Nothing (Just x) = Just x
79 merge (Just _) (Just y) = Just y
81 -- Use only the latter usernames if there are any.
82 all_usernames = if (null (usernames cfg2))
86 instance DCT.Configured [String] where
87 convert (DCT.List xs) =
88 mapM convert_string xs
90 convert_string :: DCT.Value -> Maybe String
91 convert_string = DCT.convert
95 from_rc :: IO OptionalCfg
97 cfg <- DC.load [ DC.Optional "$(HOME)/.twatrc" ]
98 cfg_consumer_key <- DC.lookup cfg "consumer-key"
99 cfg_consumer_secret <- DC.lookup cfg "consumer-secret"
100 cfg_access_token <- DC.lookup cfg "access-token"
101 cfg_access_secret <- DC.lookup cfg "access-secret"
102 cfg_heartbeat <- DC.lookup cfg "heartbeat"
103 cfg_ignore_replies <- DC.lookup cfg "ignore-replies"
104 cfg_ignore_retweets <- DC.lookup cfg "ignore-retweets"
105 cfg_sendmail_path <- DC.lookup cfg "sendmail-path"
106 cfg_from_address <- DC.lookup cfg "from"
107 cfg_to_address <- DC.lookup cfg "to"
108 cfg_verbose <- DC.lookup cfg "verbose"
109 cfg_usernames <- DC.lookup cfg "usernames"
123 (fromMaybe [] cfg_usernames)