content: {-# LANGUAGE TemplateHaskell #-}
  
  module Config where
  
  import Data.Label
  import System.Console.GetOpt
  
  
  data Config
    = Config
    {
      _configThreshLow            :: Float
    , _configThreshHigh           :: Float
    }
  
  $(mkLabels [''Config])
  
  defaults :: Config
  defaults = Config
    { _configThreshLow            = 50
    , _configThreshHigh           = 100
    }
  
  
  options :: [OptDescr (Config -> Config)]
  options =
    [ Option  ['w'] ["threshold-low"]
              (ReqArg (set configThreshLow . read) "FLOAT")
              (describe configThreshLow "threshold value for weak edges")
  
    , Option  ['s'] ["threshold-high"]
              (ReqArg (set configThreshHigh . read) "FLOAT")
              (describe configThreshHigh "threshold value for strong edges")
    ]
    where
      describe f msg
        = msg ++ " (" ++ show (get f defaults) ++ ")"
  
  
  -- | Process the command line options
  --
  
  header :: [String]
  header =
    [ "accelerate-canny (c) [2007..2013] The Accelerate Team"
    , ""
    , "Usage: accelerate-canny [OPTIONS] fileIn.bmp fileOut.bmp"
    , ""
    ]
  
  footer :: [String]
  footer = [ "" ]
  
  