Util.hs

   1 module Util (
   2     Operation (..),
   3     isHelp,
   4     parseArg,
   5     progName,
   6     progVersion,
   7     usage
   8 ) where
   9
  10 import System.Environment
  11
  12 progName = "hdata"
  13 progVersion = "0.0"
  14
  15 data Operation = Add
  16                | Bookmark
  17                | Citation
  18                | Help
  19                | Modify
  20                | Remove
  21                | Search
  22                | View
  23                | Version
  24                deriving (Show)
  25
  26 isHelp :: String -> Bool
  27 isHelp str = str `elem` ["-h","help","--help"]
  28
  29 usage :: Operation -> String
  30 usage op = show op ++ " not yet implemented"
  31
  32 parseArg :: String -> Either String Operation
  33 parseArg op = case op of
  34     "add"      -> Right Add
  35     "bookmark" -> Right Bookmark
  36     "citation" -> Right Citation
  37     "help"     -> Right Help
  38     "-h"       -> Right Help
  39     "--help"   -> Right Help
  40     "modify"   -> Right Modify
  41     "remove"   -> Right Remove
  42     "search"   -> Right Search
  43     "view"     -> Right View
  44     "version"  -> Right Version
  45     _          -> Left $ "Invalid argument: " ++ op
  46
  47