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Added error for each missing file.

Generalised the allExist function to findMissing.
pull/21/head
Anton Golov 8 years ago
parent
commit
c5a29ef171
  1. 42
      Lamb.hs

42
Lamb.hs

@ -5,18 +5,18 @@
import System.Environment (getArgs)
import System.Directory (doesFileExist)
import System.FilePath (FilePath, splitExtension)
import Control.Applicative ((<$>))
import Control.Monad (filterM)
import Control.Monad.IO.Class (liftIO)
import Parser (parseProgram)
import Interp (evalFileV, evalProgram, initIO, interpret, InterpState, Value)
-- returns Nothing if all files exist, or Just path for the first one that doesn't
allExist :: [FilePath] -> IO (Maybe FilePath)
allExist [] = return Nothing
allExist ("-":xs) = allExist xs
allExist (x:xs) = do
exists <- doesFileExist x
if exists then allExist xs
else return $ Just x
exists :: FilePath -> IO Bool
exists "-" = return True
exists path = not <$> doesFileExist path
findMissing :: [FilePath] -> IO [FilePath]
findMissing = filterM exists
repl :: InterpState Value
repl = do
@ -25,24 +25,26 @@ repl = do
case parseProgram line of
Left err -> do
liftIO $ putStrLn $ "parse error: " ++ show err
repl
Right prg -> do
ev <- evalProgram prg
liftIO $ print ev
repl
repl
repl' :: IO ()
repl' = interpret repl >> return ()
main = do
args <- getArgs
case args of
[] -> -- no arguments, launch REPL
initIO >> repl'
_ -> do
exist <- allExist args
case exist of
Just file -> putStrLn $ "error: file " ++ file ++ " doesn't exist"
Nothing ->
initIO >>
mapM_ evalFileV args
if null args
then do -- no arguments, launch REPL
initIO
repl'
else do
missing <- findMissing args
if null missing
then do
initIO
mapM_ evalFileV args
else do
let reportMissing file = putStrLn $ "error: file " ++ file ++ " doesn't exist"
mapM_ reportMissing missing

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