{-# LANGUAGE DeriveDataTypeable, GeneralizedNewtypeDeriving, Rank2Types #-} -- Copyright (c) 2008 Jean-Philippe Bernardy -- | Haskell-specific modes and commands. module Yi.Mode.Haskell ( -- * Modes cleverMode, preciseMode, literateMode, fastMode, -- * IO-level operations ghciGet, ghciLoadBuffer ) where import Data.Binary import Data.List (dropWhile, takeWhile, filter, drop) import Data.Maybe (maybe, listToMaybe, isJust, catMaybes) import Prelude (unwords) import Yi.Core import Yi.File import Yi.Lexer.Alex (Tok(..),Posn(..),tokBegin,tokEnd,tokRegion) import Yi.Lexer.Haskell (Token(..), ReservedType(..), startsLayout) import Yi.Prelude import Yi.Region import Yi.String import Yi.Syntax import Yi.Syntax.Haskell as Hask import Yi.Syntax.Paren as Paren import Yi.Syntax.Tree import Yi.Syntax.OnlineTree as OnlineTree import qualified Yi.IncrementalParse as IncrParser import qualified Yi.Lexer.Alex as Alex import qualified Yi.Lexer.LiterateHaskell as LiterateHaskell import Yi.Lexer.Haskell as Haskell import qualified Yi.Mode.Interactive as Interactive import Yi.Modes (anyExtension, extensionOrContentsMatch) haskellAbstract :: Mode syntax haskellAbstract = emptyMode { modeApplies = extensionOrContentsMatch extensions shebangPattern, modeName = "haskell", modeToggleCommentSelection = toggleCommentSelectionB "-- " "--" } {- Some of these are a little questionably haskell related. For example ".x" is an alex lexer specification I dare say that there are other file types that use ".x" as the file extension. For now though this is probably okay given the users of 'yi' are mostly haskell hackers, as of yet. -} where extensions = ["hs", "x", "hsc", "hsinc"] shebangPattern = "^#![[:space:]]*/usr/bin/env[[:space:]]+runhaskell" -- | "Clever" haskell mode, using the paren-matching syntax. cleverMode :: Mode (Expr (Tok Haskell.Token)) cleverMode = haskellAbstract { modeIndent = cleverAutoIndentHaskellB, modeGetStrokes = \t point begin end -> Paren.getStrokes point begin end t, modeHL = ExtHL $ mkHighlighter (skipScanner 50 . IncrParser.scanner Paren.parse . Paren.indentScanner . haskellLexer) , modeAdjustBlock = adjustBlock , modePrettify = cleverPrettify , modeGetAnnotations = tokenBasedAnnots Paren.tokenToAnnot } fastMode :: Mode (OnlineTree.TreeAtPos TT) fastMode = haskellAbstract { modeName = "fast haskell", modeHL = ExtHL $ mkHighlighter (IncrParser.scanner OnlineTree.manyToks . haskellLexer), modeGetStrokes = tokenBasedStrokes Paren.tokenToStroke, modeGetAnnotations = tokenBasedAnnots Paren.tokenToAnnot } literateMode :: Mode [Paren.Tree TT] literateMode = haskellAbstract { modeName = "literate haskell" , modeApplies = anyExtension ["lhs"] , modeHL = ExtHL $ mkHighlighter (IncrParser.scanner Paren.parse . Paren.indentScanner . literateHaskellLexer) , modeGetStrokes = \t point begin end -> Paren.getStrokes point begin end t , modeGetAnnotations = \t _begin -> catMaybes $ fmap Paren.tokenToAnnot $ allToks t -- FIXME I think that 'begin' should not be ignored , modeAdjustBlock = adjustBlock , modeIndent = cleverAutoIndentHaskellB , modePrettify = cleverPrettify } -- | Experimental Haskell mode, using a rather precise parser for the syntax. preciseMode :: Mode (Hask.Tree TT) preciseMode = haskellAbstract { modeName = "precise haskell", -- modeIndent = cleverAutoIndentHaskellB, modeGetStrokes = \ast point begin end -> Hask.getStrokes point begin end ast, modeHL = ExtHL $ mkHighlighter (IncrParser.scanner Hask.parse . Hask.indentScanner . haskellLexer) --} -- , modeAdjustBlock = adjustBlock -- , modePrettify = cleverPrettify } haskellLexer = Alex.lexScanner Haskell.alexScanToken Haskell.initState literateHaskellLexer = Alex.lexScanner LiterateHaskell.alexScanToken LiterateHaskell.initState adjustBlock :: Expr (Tok Token) -> Int -> BufferM () adjustBlock e len = do p <- pointB l <- curLn let t = Paren.getIndentingSubtree e p l case t of Nothing -> return () Just it -> savingExcursionB $ do let (_startOfs, height) = Paren.getSubtreeSpan it col <- curCol forM_ [1..height] $ const $ do lineDown indent <- indentOfB =<< readLnB -- it might be that we have 1st column comments in the block, -- which should not be changed. when (indent > col) $ if len >= 0 then do insertN (replicate len ' ') leftN len else do deleteN (negate len) -- | Returns true if the token should be indented to look as "inside" the group. insideGroup :: Token -> Bool insideGroup (Special c) = c `notElem` "',;})]" insideGroup _ = True cleverAutoIndentHaskellB :: Expr TT -> IndentBehaviour -> BufferM () cleverAutoIndentHaskellB e behaviour = do indentSettings <- indentSettingsB let indentLevel = shiftWidth indentSettings previousIndent <- indentOfB =<< getNextNonBlankLineB Backward nextIndent <- indentOfB =<< getNextNonBlankLineB Forward solPnt <- pointAt moveToSol eolPnt <- pointAt moveToEol let onThisLine ofs = ofs >= solPnt && ofs <= eolPnt firstTokNotOnLine = listToMaybe . filter (not . onThisLine . posnOfs . tokPosn) . filter (not . isErrorTok . tokT) . allToks let stopsOf :: [Paren.Tree TT] -> [Int] stopsOf (g@(Paren.Paren open ctnt close):ts) | isErrorTok (tokT close) || getLastOffset g >= solPnt = [groupIndent open ctnt] -- stop here: we want to be "inside" that group. | otherwise = stopsOf ts -- this group is closed before this line; just skip it. stopsOf ((Paren.Atom (Tok {tokT = t})):_) | startsLayout t = [nextIndent, previousIndent + indentLevel] -- of; where; etc. we want to start the block here. -- Also use the next line's indent: -- maybe we are putting a new 1st statement in the block here. stopsOf ((Paren.Atom _):ts) = stopsOf ts -- any random part of expression, we ignore it. stopsOf (t@(Paren.Block _):ts) = shiftBlock + maybe 0 (posnCol . tokPosn) (getFirstElement t) : stopsOf ts stopsOf (Paren.Error _:ts) = stopsOf ts stopsOf [] = [] firstTokOnLine = fmap tokT $ listToMaybe $ dropWhile ((solPnt >) . tokBegin) $ takeWhile ((eolPnt >) . tokBegin) $ -- for laziness. filter (not . isErrorTok . tokT) $ allToks e shiftBlock = case firstTokOnLine of Just (Reserved t) | t `elem` [Where, Deriving] -> indentLevel Just (ReservedOp Haskell.Pipe) -> indentLevel Just (ReservedOp Haskell.Equal) -> indentLevel _ -> 0 deepInGroup = maybe True insideGroup firstTokOnLine groupIndent (Tok {tokT = Special openChar, tokPosn = Posn _ _ openCol}) ctnt | deepInGroup = case firstTokNotOnLine ctnt of -- examine the first token of the group (but not on the line we are indenting!) Nothing -> openCol + nominalIndent openChar -- no such token: indent normally. Just t -> posnCol . tokPosn $ t -- indent along that other token | otherwise = openCol case getLastPath e solPnt of Nothing -> return () Just path -> let stops = stopsOf path in trace ("Stops = " ++ show stops) $ trace ("firstTokOnLine = " ++ show firstTokOnLine) $ cycleIndentsB behaviour stops nominalIndent :: Char -> Int nominalIndent '{' = 2 nominalIndent _ = 1 tokText :: Tok t -> BufferM String tokText = readRegionB . tokRegion isLineComment :: TT -> Bool isLineComment = (Just Haskell.Line ==) . tokTyp . tokT contiguous :: forall t. Tok t -> Tok t -> Bool contiguous a b = lb - la <= 1 where [la,lb] = fmap (posnLine . tokPosn) [a,b] coalesce :: Tok Token -> Tok Token -> Bool coalesce a b = isLineComment a && isLineComment b && contiguous a b cleverPrettify :: Expr TT -> BufferM () cleverPrettify e = do pnt <- pointB let toks = allToks e groups = groupBy' coalesce toks isCommentGroup g = (tokTyp $ tokT $ head $ g) `elem` fmap Just [Haskell.Line] thisCommentGroup = listToMaybe $ dropWhile ((pnt >) . tokEnd . last) $ filter isCommentGroup $ groups -- FIXME: laziness case thisCommentGroup of Nothing -> return () Just g -> do let region = mkRegion (tokBegin . head $ g) (tokEnd . last $ g) text <- unwords . fmap (drop 2) <$> mapM tokText g modifyRegionClever (const $ unlines' $ fmap ("-- " ++) $ fillText 80 $ text) region tokTyp :: Token -> Maybe Haskell.CommentType tokTyp (Comment t) = Just t tokTyp _ = Nothing -- | Keyword-based auto-indenter for haskell. autoIndentHaskellB :: IndentBehaviour -> BufferM () autoIndentHaskellB = autoIndentWithKeywordsB [ "if" , "then" , "else" , "|" , "->" , "case" -- hmm , "in" -- Note tempted by having '=' in here that would -- potentially work well for 'data' declarations -- but I think '=' is so common in other places -- that it would introduce many spurious/annoying -- hints. ] [ "where" , "let" , "do" , "mdo" , "{-" , "{-|" , "--" ] --------------------------- -- * Interaction with GHCi newtype GhciBuffer = GhciBuffer {_ghciBuffer :: Maybe BufferRef} deriving (Initializable, Typeable, Binary) -- | Start GHCi in a buffer ghci :: YiM BufferRef ghci = do b <- Interactive.interactive "ghci" [] withEditor $ setDynamic $ GhciBuffer $ Just b return b -- | Return GHCi's buffer; create it if necessary. -- Show it in another window. ghciGet :: YiM BufferRef ghciGet = withOtherWindow $ do GhciBuffer mb <- withEditor $ getDynamic case mb of Nothing -> ghci Just b -> do stillExists <- withEditor $ isJust <$> findBuffer b if stillExists then do withEditor $ switchToBufferE b return b else ghci -- | Send a command to GHCi ghciSend :: String -> YiM () ghciSend cmd = do b <- ghciGet withGivenBuffer b botB sendToProcess b (cmd ++ "\n") -- | Load current buffer in GHCi ghciLoadBuffer :: YiM () ghciLoadBuffer = do fwriteE Just filename <- withBuffer $ gets file ghciSend $ ":load " ++ filename