-module Parse ( ekitaiOpts ) where
+module Parse ( ekitaiOpts, optTimeStep, hGetLines ) where
import System.Console.GetOpt
import System.Environment
+import System.Exit
+import System.IO
import Data.Maybe
import Data.Either
data Options = Options
- { optHelp :: Bool
- , optColor :: Bool
+ { optTimeStep :: Int
}
defaultOptions = Options
- { optHelp = False
- , optColor = False
+ { optTimeStep = 50000
}
options :: [OptDescr (Options -> Options)]
options =
- [ Option ['h'] ["help"]
- (NoArg (\ opts -> opts { optHelp = True }))
- "display's this message"
- , Option ['c'] ["color", "colour"]
- (NoArg (\ opts -> opts { optColor = True }))
- "enables color"
+ [ Option ['t'] ["timestep"]
+ (ReqArg (\t opts -> opts { optTimeStep = read t :: Int }) "timestep")
+ "sets the simulation time step"
]
ekitaiOpts :: [String] -> IO (Options, String)
ekitaiOpts argv =
case getOpt RequireOrder options argv of
(o, [n], []) -> return (foldl (flip id) defaultOptions o, n)
- (o, _, []) -> ioError $ userError $ "must supply input file"
- (_, _, errs) -> ioError $ userError $ (concat errs)
+ (o, _, []) -> ioError $ userError $ "missing input file"
+ (_, _, errs) -> ioError $ userError $ concat errs
+
+-- reads in file by lines
+hGetLines :: Handle -> IO [String]
+hGetLines h = do
+ line <- hGetLine h
+ isEof <- hIsEOF h
+ if isEof then return [line]
+ else do
+ lines <- hGetLines h
+ return (line:lines)
