cabal-dev-scripts/src/GenCabalInstallCabal.hs

   1 {-# LANGUAGE DeriveGeneric       #-}
   2 {-# LANGUAGE ScopedTypeVariables #-}
   3 module Main (main) where
   4
   5 import Control.Exception  (SomeException (..), catch, displayException)
   6 import GHC.Generics       (Generic)
   7 import System.Environment (getArgs)
   8 import System.Exit        (exitFailure)
   9
  10 import qualified Zinza as Z
  11
  12 withIO :: (Bool -> FilePath -> FilePath -> IO a) -> IO a
  13 withIO k = do
  14     args <- getArgs
  15     case args of
  16         [dev',src,tgt]
  17             | Just dev <- parseBool dev'
  18             -> k dev src tgt `catch` \(SomeException e) -> do
  19                 putStrLn $ "Exception: " ++ displayException e
  20                 exitFailure
  21         _         -> do
  22             putStrLn "Usage cabal run ... source.temeplate.ext target.ext"
  23             exitFailure
  24   where
  25     parseBool "True"  = Just True
  26     parseBool "False" = Just False
  27     parseBool _       = Nothing
  28
  29
  30 main :: IO ()
  31 main = withIO $ \dev src tgt -> do
  32     render <- Z.parseAndCompileTemplateIO src
  33     contents <- render $ Z dev ()
  34     writeFile tgt contents
  35
  36 -------------------------------------------------------------------------------
  37 -- Data
  38 -------------------------------------------------------------------------------
  39
  40 data Z = Z
  41     { zDev    :: Bool
  42     , zUnused :: ()
  43     }
  44   deriving (Generic)
  45
  46 instance Z.Zinza Z where
  47     toType    = Z.genericToTypeSFP
  48     toValue   = Z.genericToValueSFP
  49     fromValue = Z.genericFromValueSFP