From 788de39262809040ebf1096aff22190ad526dc1b Mon Sep 17 00:00:00 2001
From: defanor <defanor@uberspace.net>
Date: Sat, 27 Jan 2024 23:04:26 +0300
Subject: Rewrite, version 0.2: use Parsec, focus on DSV

---
 examples/Pipes.hs | 67 -------------------------------------------------------
 1 file changed, 67 deletions(-)
 delete mode 100644 examples/Pipes.hs

(limited to 'examples/Pipes.hs')

diff --git a/examples/Pipes.hs b/examples/Pipes.hs
deleted file mode 100644
index b1096e3..0000000
--- a/examples/Pipes.hs
+++ /dev/null
@@ -1,67 +0,0 @@
-{-# LANGUAGE RankNTypes, ScopedTypeVariables, DeriveGeneric,
-  DeriveAnyClass #-}
-
-module Coalpit.IO (runMain, runMain', handleErrors) where
-
-import Data.Proxy (Proxy(..))
-import System.Environment (getProgName, getArgs)
-import Control.Monad.IO.Class (MonadIO, liftIO)
-import System.Exit (die)
-import System.IO (hPutStrLn, stderr)
-import Pipes ((>->), Pipe, yield, await, lift, runEffect)
-import Control.Monad (mapM_, forever)
-import qualified Pipes.Prelude as PP
-import Coalpit.Core (Coalpit, fromArgs, defOpt, usage)
-import Coalpit.DSV (readDSV, showDSV)
-import GHC.Generics
-
--- | Runs a given action on each 'Left' value, embedding that action's
--- result into the data stream.
-handleErrors :: MonadIO m => (e -> m [a]) -> Pipe (Either e a) a m ()
-handleErrors e = forever $ do
-  v <- await
-  case v of
-    Left err -> do
-      vs <- lift $ e err
-      mapM_ yield vs
-    Right x -> yield x
-
--- | Runs a given 'Pipe' between input producer and output consumer.
--- Prints an error and usage instructions if it fails to parse the
--- arguments, and passes the input through 'handleErrors'.
-runMain :: forall m a i o. (MonadIO m, Coalpit a, Coalpit i, Coalpit o)
-        => (String -> m [i])
-        -- ^ An action to run on error (see 'handleErrors').
-        -> (a -> Pipe i o m ())
-        -- ^ Main function.
-        -> m ()
-runMain e f = do
-  pn <- liftIO getProgName
-  let u = Prelude.concat [ "Usage: ", pn, " "
-                         , usageString defOpt (Proxy :: Proxy a)]
-  args <- liftIO getArgs
-  a <- either (liftIO . die . (++ u)) pure $ fromArgs defOpt args
-  runEffect $
-    PP.stdinLn
-    >-> PP.map (readDSV defOpt)
-    >-> handleErrors e
-    >-> f a
-    >-> PP.map (showDSV defOpt)
-    >-> PP.stdoutLn
-
--- | Same as 'runMain', but just prints errors into 'stderr'.
-runMain' :: forall m a i o. (MonadIO m, Coalpit a, Coalpit i, Coalpit o)
-         => (a -> Pipe i o m ())
-         -- ^ Main function.
-         -> m ()
-runMain' = runMain (\e -> liftIO $ hPutStrLn stderr e >> pure [])
-
-
-data Args = Args { arg1 :: Maybe Int, arg2 :: Double }
-  deriving (Generic, Coalpit)
-data Input = Input Double deriving (Generic, Coalpit)
-data Output = Foo Double | Bar deriving (Generic, Coalpit)
-
-main :: IO ()
-main = runMain' $ \a -> PP.mapM $ \(Input i) ->
-  pure $ Foo $ maybe (arg2 a) fromIntegral (arg1 a) + i
-- 
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