hdata.hs

   1 import System.Environment
   2
   3 progName = "hdata"
   4 progVersion = "0.0"
   5
   6 data Operation = Add
   7                | Bookmark
   8                | Citation
   9                | Help
  10                | Modify
  11                | Remove
  12                | Search
  13                | View
  14                | Version
  15                deriving (Show)
  16
  17 usage :: Operation -> String
  18
  19 usage Help = "usage: " ++ progName ++ " [operation] [id]\n\
  20              \operations:\n\
  21              \    add                  <filters>     \n\
  22              \    bookmark [options]             [id]\n\
  23              \    citation [options]             [id]\n\
  24              \    help     [operation]               \n\
  25              \    modify   [options]   <filters> <id>\n\
  26              \    remove   [options]             <id>\n\
  27              \    search   [options]   [filters] [id]\n\
  28              \    view     [options]             <id>\n\
  29              \    version\n"
  30
  31 usage op = show op ++ " not yet implemented"
  32
  33 parseArgs :: [String] -> Either String Operation
  34 parseArgs [] = Left $ "No operation specified ('" ++ progName ++ " help' for help)"
  35 parseArgs xs = parseArg $ head xs
  36
  37 parseArg :: String -> Either String Operation
  38 parseArg op = case op of
  39     "add"      -> Right Add
  40     "bookmark" -> Right Bookmark
  41     "citation" -> Right Citation
  42     "help"     -> Right Help
  43     "-h"       -> Right Help
  44     "--help"   -> Right Help
  45     "modify"   -> Right Modify
  46     "remove"   -> Right Remove
  47     "search"   -> Right Search
  48     "view"     -> Right View
  49     "version"  -> Right Version
  50     _          -> Left $ "Invalid argument: " ++ op
  51
  52 add :: [String] -> IO ()
  53 add argv = putStrLn $ usage Add
  54
  55 bookmark :: [String] -> IO ()
  56 bookmark argv = putStrLn $ usage Bookmark
  57
  58 citation :: [String] -> IO ()
  59 citation argv = putStrLn $ usage Citation
  60
  61 help :: [String] -> IO ()
  62 help argv = putStrLn $ usage Help
  63
  64 modify :: [String] -> IO ()
  65 modify argv = putStrLn $ usage Modify
  66
  67 remove :: [String] -> IO ()
  68 remove argv = putStrLn $ usage Remove
  69
  70 search :: [String] -> IO ()
  71 search argv = putStrLn $ usage Search
  72
  73 view :: [String] -> IO ()
  74 view argv = putStrLn $ usage View
  75
  76 version :: IO ()
  77 version = putStrLn $ progName ++ " " ++ progVersion
  78
  79 main :: IO ()
  80 main = do
  81     argv <- getArgs
  82     let argv' = tail argv
  83     case parseArgs argv of
  84         Right Add      -> add argv'
  85         Right Bookmark -> bookmark argv'
  86         Right Citation -> citation argv'
  87         Right Help     -> help argv'
  88         Right Modify   -> modify argv'
  89         Right Remove   -> remove argv'
  90         Right Search   -> search argv'
  91         Right View     -> view argv'
  92         Right Version  -> version
  93         Left msg       -> error msg
  94
  95
  96