X-Git-Url: http://gitweb.michael.orlitzky.com/?p=dead%2Fhalcyon.git;a=blobdiff_plain;f=src%2FCommandLine.hs;h=da6a04b06b35e2f2cdf3472bb68d53311611e05c;hp=c5ddb4b48a002213631cbdb32d0f91596a399db1;hb=69b8af30f49aaad0f5c051998d2556b9ec291df7;hpb=17dd116706c4a971e1f5c68daa1656af5eff5cd2 diff --git a/src/CommandLine.hs b/src/CommandLine.hs index c5ddb4b..da6a04b 100644 --- a/src/CommandLine.hs +++ b/src/CommandLine.hs @@ -1,7 +1,6 @@ --- The CommandLine module handles parsing of the command-line options. +-- |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, help_text, @@ -17,27 +16,27 @@ import System.Environment (getArgs) --- A record containing values for all available options. +-- |A record containing values for all available options. data Options = Options { opt_help :: Bool, opt_from :: Maybe String, opt_to :: Maybe String } --- This 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, opt_from = Nothing, opt_to = Nothing } --- The options list that we construct associates a function with each +-- |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, -- --- http://www.haskell.org/haskellwiki/High-level_option_handling_with_GetOpt +-- -- options :: [OptDescr (Options -> IO Options)] options = @@ -45,7 +44,7 @@ options = Option ['t'][] (ReqArg set_to "email_address") "Send tweets TO email_address.", Option ['f'][] (ReqArg set_from "email_address") "Send tweets FROM email_address." ] - + set_help :: Options -> IO Options set_help opts = do @@ -58,7 +57,7 @@ set_to arg opts = do set_from :: String -> Options -> IO Options set_from arg opts = do return opts { opt_from = Just arg } - + -- The usage header. usage :: String @@ -85,6 +84,7 @@ parse_options = do return opts +-- |Parse errors relating to the list of usernames. username_errors :: IO [String] username_errors = do argv <- getArgs @@ -95,6 +95,7 @@ username_errors = do else return [] +-- |Parse errors relating to the "To" address. to_errors :: IO [String] to_errors = do toaddr <- to_email_address @@ -103,6 +104,8 @@ to_errors = do then return ["\"From\" address specified without \"To\" address."] else return [] + +-- |Parse errors relating to the "From" address. from_errors :: IO [String] from_errors = do toaddr <- to_email_address @@ -112,38 +115,42 @@ from_errors = do else return [] +-- |Format an error message for printing. format_error :: String -> String format_error err = "ERROR: " ++ err ++ "\n" --- Return a list of errors. +-- |Return a list of all parse errors. parse_errors :: IO [String] parse_errors = do argv <- getArgs - let (_, _, errors) = getOpt Permute options argv + let (_, _, errors) = getOpt Permute options argv errs_username <- username_errors errs_to <- to_errors errs_from <- from_errors return $ map format_error (errors ++ errs_username ++ errs_to ++ errs_from) --- Is the help option set? +-- |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? parse_usernames :: IO [String] parse_usernames = do argv <- getArgs