blob: a04564770076639d21cc5fca39e3db8ff8322b4b (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
module Minilang.IO where
import qualified Data.ByteString as BS
import qualified Data.Text as Text
import Data.Text.Encoding
( decodeUtf8With,
encodeUtf8,
)
import Data.Text.Encoding.Error (lenientDecode)
import Minilang.Lambda.DeBruijn (eval, toDeBruijn)
import Minilang.Lambda.Parser (desugar, parse, pretty)
import System.IO (Handle)
-- | Read a "program" 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 parsed = parse programText
case parsed of
Left err -> print err
Right ast -> do
putStrLn $ Text.unpack $ "Evaluating " <> pretty ast
let termy = desugar ast
putStrLn $ "Desugared to " <> show termy
let term = toDeBruijn termy
print $ eval term
|
