--- |The CommandLine module handles parsing of the command-line options.
--- It should more or less be a black box, providing Main with only the
--- information it requires.
+-- | The CommandLine module handles parsing of the command-line
+-- options. It should more or less be a black box, providing Main
+-- with only the information it requires.
module CommandLine
-( help_set,
+( get_cfg,
+ help_set,
help_text,
- from_email_address,
- to_email_address,
parse_errors,
parse_usernames
) where
-import Data.Maybe (isJust, isNothing)
+import Data.Maybe (fromJust, isJust, isNothing)
import System.Console.GetOpt
import System.Environment (getArgs)
+import Configuration (Cfg(..))
-
--- |A record containing values for all available options.
-data Options = Options { opt_help :: Bool,
+-- | A record containing values for all available options.
+data Options = Options { opt_heartbeat :: Maybe Int,
+ opt_help :: Bool,
+ opt_ignore_replies :: Bool,
+ opt_ignore_retweets :: Bool,
opt_from :: Maybe String,
- opt_to :: Maybe String }
+ opt_to :: Maybe String,
+ opt_verbose :: Bool }
--- |Constructs an instance of Options, with each of its members set to
--- default values.
+-- | Constructs an instance of Options, with each of its members set
+-- to default values.
default_options :: Options
-default_options = Options { opt_help = False,
+default_options = Options { opt_heartbeat = Just 600,
+ opt_help = False,
+ opt_ignore_replies = False,
+ opt_ignore_retweets = False,
opt_from = Nothing,
- opt_to = Nothing }
+ opt_to = Nothing,
+ opt_verbose = False }
--- |The options list that we construct associates a function with each
--- option. This function is responsible for updating an Options record
--- with the appropriate value.
+-- | The options list that we construct associates a function with
+-- each option. This function is responsible for updating an Options
+-- record with the appropriate value.
--
--- For more information and an example of this idiom, see,
+-- For more information and an example of this idiom, see,
--
--- <http://www.haskell.org/haskellwiki/High-level_option_handling_with_GetOpt>
+-- <http://www.haskell.org/haskellwiki/High-level_option_handling_with_GetOpt>
--
options :: [OptDescr (Options -> IO Options)]
options =
- [ Option ['h'][] (NoArg set_help) "Prints this help message.",
- Option ['t'][] (ReqArg set_to "email_address") "Send tweets TO email_address.",
- Option ['f'][] (ReqArg set_from "email_address") "Send tweets FROM email_address."
+ [ Option
+ ['h']["help"]
+ (NoArg set_help)
+ "Prints this help message.",
+
+ Option
+ ['n']["heartbeat"]
+ (ReqArg set_heartbeat "heartbeat")
+ "How many seconds to wait between polling.",
+
+ Option
+ ['t']["to"]
+ (ReqArg set_to "email_address")
+ "Send tweets TO email_address.",
+
+ Option
+ ['f']["from"]
+ (ReqArg set_from "email_address")
+ "Send tweets FROM email_address.",
+
+ Option
+ ['i']["ignore-replies"]
+ (NoArg set_ignore_replies)
+ "Ignore replies.",
+
+ Option
+ ['I']["ignore-retweets"]
+ (NoArg set_ignore_retweets)
+ "Ignore retweets.",
+
+ Option
+ ['v']["verbose"]
+ (NoArg set_verbose)
+ "Be verbose about stuff."
]
+-- | Attempt to parse an 'Int' from a 'String'. This is just a 'Maybe'
+-- wrapper around 'reads'.
+parse_int :: String -> Maybe Int
+parse_int s =
+ case (reads s) of
+ [(n,_)] -> Just n
+ _ -> Nothing
+
+set_heartbeat :: String -> Options -> IO Options
+set_heartbeat arg opts = do
+ let new_heartbeat = parse_int arg
+ return opts { opt_heartbeat = new_heartbeat }
+
set_help :: Options -> IO Options
set_help opts = do
return opts { opt_help = True }
+set_ignore_retweets :: Options -> IO Options
+set_ignore_retweets opts =
+ return opts { opt_ignore_retweets = True }
+
+set_ignore_replies :: Options -> IO Options
+set_ignore_replies opts =
+ return opts { opt_ignore_replies = True }
+
+set_verbose :: Options -> IO Options
+set_verbose opts =
+ return opts { opt_verbose = True }
+
set_to :: String -> Options -> IO Options
set_to arg opts = do
return opts { opt_to = Just arg }
return opts { opt_from = Just arg }
--- The usage header.
+-- | The usage header.
usage :: String
-usage = "Usage: twat [-t to_address] [-f from_address] <username1> [username2, [username3]...]"
+usage = "Usage: twat [-n heartbeat] [-t to_address] [-f from_address] <username1> [username2, [username3]...]"
--- The usage header, and all available flags (as generated by GetOpt)
+-- | Was the help option passed?
+help_set :: IO Bool
+help_set = do
+ opts <- parse_options
+ return (opt_help opts)
+
+-- | The usage header, and all available flags (as generated by GetOpt)
help_text :: String
help_text = usageInfo usage options
--- Return a list of options.
+-- | Return a list of options.
parse_options :: IO Options
parse_options = do
argv <- getArgs
return opts
+-- | A list of parse errors relating to the heartbeat.
+heartbeat_errors :: IO [String]
+heartbeat_errors = do
+ hb <- parse_heartbeat
+ if (isNothing hb)
+ then return ["\"heartbeat\" does not appear to be an integer."]
+ else return []
+
-- |Parse errors relating to the list of usernames.
username_errors :: IO [String]
username_errors = do
let (_, usernames, _) = getOpt Permute options argv
if (null usernames)
- then return ["No usernames provided."]
+ then return ["no usernames provided."]
else return []
-- |Parse errors relating to the "To" address.
to_errors :: IO [String]
to_errors = do
- toaddr <- to_email_address
- fromaddr <- from_email_address
+ toaddr <- parse_to_address
+ fromaddr <- parse_from_address
if (isNothing toaddr) && (isJust fromaddr)
- then return ["\"From\" address specified without \"To\" address."]
+ then return ["\"from\" address specified without \"to\" address."]
else return []
--- |Parse errors relating to the "From" address.
+-- | Parse errors relating to the "From" address.
from_errors :: IO [String]
from_errors = do
- toaddr <- to_email_address
- fromaddr <- from_email_address
+ toaddr <- parse_to_address
+ fromaddr <- parse_from_address
if (isJust toaddr) && (isNothing fromaddr)
- then return ["\"To\" address specified without \"From\" address."]
+ then return ["\"to\" address specified without \"from\" address."]
else return []
--- |Format an error message for printing.
+-- | Format an error message for printing.
format_error :: String -> String
format_error err = "ERROR: " ++ err ++ "\n"
--- |Return a list of all parse errors.
+-- | Return a list of all parse errors.
parse_errors :: IO [String]
parse_errors = do
argv <- getArgs
let (_, _, errors) = getOpt Permute options argv
+ errs_heartbeat <- heartbeat_errors
errs_username <- username_errors
errs_to <- to_errors
errs_from <- from_errors
- return $ map format_error (errors ++ errs_username ++ errs_to ++ errs_from)
-
--- |Was the "help" option passed on the command line?
-help_set :: IO Bool
-help_set = do
- opts <- parse_options
- return (opt_help opts)
-
-
--- |What "To" address was given on the command line?
-to_email_address :: IO (Maybe String)
-to_email_address = do
- opts <- parse_options
- return (opt_to opts)
-
--- |What "From" address was given on the command line?
-from_email_address :: IO (Maybe String)
-from_email_address = do
- opts <- parse_options
- return (opt_from opts)
-
-
--- |What usernames were passed on the command line?
+ return $ map format_error (errors ++
+ errs_heartbeat ++
+ errs_username ++
+ errs_to ++
+ errs_from)
+
+-- | What's the heartbeat?
+parse_heartbeat :: IO (Maybe Int)
+parse_heartbeat = do
+ opts <- parse_options
+ return (opt_heartbeat opts)
+
+-- | What "To" address was given on the command line?
+parse_to_address :: IO (Maybe String)
+parse_to_address = do
+ opts <- parse_options
+ return (opt_to opts)
+
+-- | What "From" address was given on the command line?
+parse_from_address :: IO (Maybe String)
+parse_from_address = do
+ opts <- parse_options
+ return (opt_from opts)
+
+
+-- | What usernames were passed on the command line?
parse_usernames :: IO [String]
parse_usernames = do
argv <- getArgs
let (_, usernames, _) = getOpt Permute options argv
return usernames
+
+
+
+-- | Construct a Cfg object from the command line options assuming
+-- there are no errors.
+get_cfg :: IO Cfg
+get_cfg = do
+ opts <- parse_options
+ return Cfg { heartbeat = fromJust $ opt_heartbeat opts,
+ ignore_replies = opt_ignore_replies opts,
+ ignore_retweets = opt_ignore_retweets opts,
+ from_address = opt_from opts,
+ to_address = opt_to opts,
+ verbose = opt_verbose opts }