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import Minilang.REPL (evaluatorFromEnv, withIO, withTerminal)
import Minilang.REPL.Types (Evaluator (..))
import Minilang.Server (startServer, waitServer)
import Options.Applicative
import System.IO (stdin, stdout)
import System.Posix.IO (stdInput)
import System.Posix.Terminal (queryTerminal)
import Text.Read (readMaybe)
data RunMode
= Local
| Server
deriving (Eq, Show)
data Options = Options
{ serverPort :: Int,
runMode :: RunMode,
-- | 'Nothing' means "read from MINILANG_EVAL env var".
evalOpt :: Maybe Evaluator
}
deriving (Eq, Show)
optionsParser :: ParserInfo Options
optionsParser =
info
(helper <*> minilangOptions)
( header "Minilang"
<> fullDesc
)
minilangOptions :: Parser Options
minilangOptions =
Options <$> portOption <*> runModeOption <*> evalOption
portOption :: Parser Int
portOption =
option
auto
( long "port"
<> short 'p'
<> value 7890
<> metavar "INT"
<> help "port to listen on (default: 7890)"
)
runModeOption :: Parser RunMode
runModeOption =
flag
Local
Server
( long "server"
<> short 'S'
<> help "run in server mode, listening for client REPLs over HTTP"
)
evalOption :: Parser (Maybe Evaluator)
evalOption =
optional $
option
(eitherReader parseEvaluator)
( long "eval"
<> short 'E'
<> metavar "EVALUATOR"
<> help "reduction strategy: DeBruijn (default) or NbE. \
\Falls back to the MINILANG_EVAL environment variable."
)
parseEvaluator :: String -> Either String Evaluator
parseEvaluator s = case readMaybe s of
Just ev -> Right ev
Nothing -> Left $ "Unknown evaluator: " <> show s <> ". Valid values: DeBruijn, NbE"
main :: IO ()
main = do
Options {..} <- execParser optionsParser
-- CLI flag takes precedence; fall back to env var.
ev <- maybe evaluatorFromEnv pure evalOpt
case runMode of
Local -> do
hasTty <- queryTerminal stdInput
if hasTty
then withTerminal ev
else withIO ev stdin stdout
Server -> startServer serverPort ev >>= waitServer
|
