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Diffstat (limited to 'main/Terminal.hs')
| -rw-r--r-- | main/Terminal.hs | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/main/Terminal.hs b/main/Terminal.hs new file mode 100644 index 0000000..d117640 --- /dev/null +++ b/main/Terminal.hs @@ -0,0 +1,241 @@ +module Terminal ( + Terminal, + hasTerminalUI, + withTerminal, + setPrompt, + getInputLine, + InputHandling(..), + + TerminalLine, + printLine, + + CompletionFunc, Completion, + simpleCompletion, + completeWordWithPrev, +) where + +import Control.Arrow +import Control.Concurrent +import Control.Concurrent.STM +import Control.Exception +import Control.Monad + +import Data.Char + +import System.IO +import System.Console.ANSI + + +data Terminal = Terminal + { termLock :: MVar () + , termAnsi :: Bool + , termPrompt :: TVar String + , termShowPrompt :: TVar Bool + , termInput :: TVar ( String, String ) + } + +data TerminalLine = TerminalLine + { tlTerminal :: Terminal + } + +data Input + = InputChar Char + | InputMoveRight + | InputMoveLeft + | InputMoveEnd + | InputMoveStart + | InputBackspace + | InputClear + | InputBackWord + | InputEnd + | InputEscape String + deriving (Eq, Ord, Show) + + +data InputHandling a + = KeepPrompt a + | ErasePrompt a + + +hasTerminalUI :: Terminal -> Bool +hasTerminalUI = termAnsi + +initTerminal :: IO Terminal +initTerminal = do + termLock <- newMVar () + termAnsi <- hNowSupportsANSI stdout + termPrompt <- newTVarIO "" + termShowPrompt <- newTVarIO False + termInput <- newTVarIO ( "", "" ) + return Terminal {..} + +bracketSet :: IO a -> (a -> IO b) -> a -> IO c -> IO c +bracketSet get set val = bracket (get <* set val) set . const + +withTerminal :: CompletionFunc IO -> (Terminal -> IO a) -> IO a +withTerminal _ act = do + term <- initTerminal + + bracketSet (hGetEcho stdin) (hSetEcho stdin) False $ + bracketSet (hGetBuffering stdin) (hSetBuffering stdin) NoBuffering $ + bracketSet (hGetBuffering stdout) (hSetBuffering stdout) (BlockBuffering Nothing) $ + act term + + +termPutStr :: Terminal -> String -> IO () +termPutStr Terminal {..} str = do + withMVar termLock $ \_ -> do + putStr str + hFlush stdout + + +getInput :: IO Input +getInput = do + getChar >>= \case + '\ESC' -> do + esc <- readEsc + case parseEsc esc of + Just ( 'C' , [] ) -> return InputMoveRight + Just ( 'D' , [] ) -> return InputMoveLeft + _ -> return (InputEscape esc) + '\b' -> return InputBackspace + '\DEL' -> return InputBackspace + '\NAK' -> return InputClear + '\ETB' -> return InputBackWord + '\SOH' -> return InputMoveStart + '\ENQ' -> return InputMoveEnd + '\EOT' -> return InputEnd + c -> return (InputChar c) + where + readEsc = getChar >>= \case + c | c == '\ESC' || isAlpha c -> return [ c ] + | otherwise -> (c :) <$> readEsc + + parseEsc = \case + '[' : c : [] -> do + Just ( c, [] ) + _ -> Nothing + + +getInputLine :: Terminal -> (Maybe String -> InputHandling a) -> IO a +getInputLine term@Terminal {..} handleResult = do + withMVar termLock $ \_ -> do + prompt <- atomically $ do + writeTVar termShowPrompt True + readTVar termPrompt + putStr prompt + hFlush stdout + (handleResult <$> go) >>= \case + KeepPrompt x -> do + termPutStr term "\n" + return x + ErasePrompt x -> do + termPutStr term "\r\ESC[K" + return x + where + go = getInput >>= \case + InputChar '\n' -> do + atomically $ do + ( pre, post ) <- readTVar termInput + writeTVar termInput ( "", "" ) + writeTVar termShowPrompt False + return $ Just $ pre ++ post + + InputChar c | isPrint c -> withInput $ \case + ( _, post ) -> do + writeTVar termInput . first (++ [ c ]) =<< readTVar termInput + return $ c : (if null post then "" else "\ESC[s" <> post <> "\ESC[u") + + InputChar _ -> go + + InputMoveRight -> withInput $ \case + ( pre, c : post ) -> do + writeTVar termInput ( pre ++ [ c ], post ) + return $ "\ESC[C" + _ -> return "" + + InputMoveLeft -> withInput $ \case + ( pre@(_ : _), post ) -> do + writeTVar termInput ( init pre, last pre : post ) + return $ "\ESC[D" + _ -> return "" + + InputBackspace -> withInput $ \case + ( pre@(_ : _), post ) -> do + writeTVar termInput ( init pre, post ) + return $ "\b\ESC[K" <> (if null post then "" else "\ESC[s" <> post <> "\ESC[u") + _ -> return "" + + InputClear -> withInput $ \_ -> do + writeTVar termInput ( "", "" ) + ("\r\ESC[K" <>) <$> getCurrentPromptLine term + + InputBackWord -> withInput $ \( pre, post ) -> do + let pre' = reverse $ dropWhile (not . isSpace) $ dropWhile isSpace $ reverse pre + writeTVar termInput ( pre', post ) + ("\r\ESC[K" <>) <$> getCurrentPromptLine term + + InputMoveStart -> withInput $ \( pre, post ) -> do + writeTVar termInput ( "", pre <> post ) + return $ "\ESC[" <> show (length pre) <> "D" + + InputMoveEnd -> withInput $ \( pre, post ) -> do + writeTVar termInput ( pre <> post, "" ) + return $ "\ESC[" <> show (length post) <> "C" + + InputEnd -> do + atomically (readTVar termInput) >>= \case + ( "", "" ) -> return Nothing + _ -> go + + InputEscape _ -> go + + withInput f = do + withMVar termLock $ const $ do + str <- atomically $ f =<< readTVar termInput + when (not $ null str) $ do + putStr str + hFlush stdout + go + + +getCurrentPromptLine :: Terminal -> STM String +getCurrentPromptLine Terminal {..} = do + prompt <- readTVar termPrompt + ( pre, post ) <- readTVar termInput + return $ prompt <> pre <> "\ESC[s" <> post <> "\ESC[u" + +setPrompt :: Terminal -> String -> IO () +setPrompt term@Terminal {..} prompt = do + withMVar termLock $ \_ -> do + join $ atomically $ do + writeTVar termPrompt prompt + readTVar termShowPrompt >>= \case + True -> do + promptLine <- getCurrentPromptLine term + return $ do + putStr $ "\r\ESC[K" <> promptLine + hFlush stdout + False -> return $ return () + +printLine :: Terminal -> String -> IO TerminalLine +printLine tlTerminal@Terminal {..} str = do + withMVar termLock $ \_ -> do + promptLine <- atomically $ do + readTVar termShowPrompt >>= \case + True -> getCurrentPromptLine tlTerminal + False -> return "" + putStr $ "\r\ESC[K" <> str <> "\n" <> promptLine + hFlush stdout + return TerminalLine {..} + + +type CompletionFunc m = ( String, String ) -> m ( String, [ Completion ] ) + +data Completion + +completeWordWithPrev :: Maybe Char -> [ Char ] -> (String -> String -> m [ Completion ]) -> CompletionFunc m +completeWordWithPrev = error "TODO" + +simpleCompletion :: String -> Completion +simpleCompletion = error "TODO" |