1 files changed, 40 insertions, 0 deletions
diff --git a/lambda-calcul/haskell/src/Minilang/IO.hs b/lambda-calcul/haskell/src/Minilang/IO.hs
new file mode 100644
index 0000000..bfcb125
--- /dev/null
+++ b/lambda-calcul/haskell/src/Minilang/IO.hs
@@ -0,0 +1,40 @@
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# OPTIONS_GHC "-fno-warn-orphans" #-}
+
+module Minilang.IO where
+
+import qualified Data.ByteString as BS
+import Data.Text.Encoding
+  ( decodeUtf8With,
+    encodeUtf8,
+  )
+import Data.Text.Encoding.Error (lenientDecode)
+import Minilang.Lambda.Eval hiding (rho)
+import Minilang.Parser
+import Minilang.Type
+import Prettyprinter
+import Prettyprinter.Render.Text
+import System.IO (Handle)
+
+-- | Read an `AST` from @hin@ handle, evaluate it and dump the result
+-- on @hout@.
+runEval :: Handle -> Handle -> IO ()
+runEval hin hout = do
+  programText <- decodeUtf8With lenientDecode <$> BS.hGetContents hin
+  let ast = parseProgram False programText
+      ρ = EmptyEnv
+      γ = EmptyContext
+  (ρ', _) <- loadProgram ast ρ γ
+  let val = eval ast ρ'
+
+  BS.hPut
+    hout
+    ( encodeUtf8
+        ( renderStrict $ layoutPretty defaultLayoutOptions $ pretty val
+        )
+        <> "\n"
+    )