PrintOrRun.hs

-- Copyright 2023-2025 Lennart Augustsson
-- See LICENSE file for full license.
module System.IO.PrintOrRun(PrintOrRun(..), _withArgs) where
import qualified Prelude()              -- do not import Prelude
import Primitives
import Data.Char(String)
import System.Environment
import System.IO
import Text.Show

-- Helper for interactive system
class PrintOrRun a where
  printOrRun :: a -> IO ()

instance PrintOrRun (IO ()) where
  printOrRun a = a

{-  Resolution of overlapping instances is not good enough for this.  Yet.
instance Show a => PrintOrRun (IO a) where
  printOrRun a = a `primBind` print
-}

instance Show a => PrintOrRun a where
  printOrRun = print

_withArgs :: [String] -> IO () -> IO ()
_withArgs = withArgs