{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE OverloadedStrings #-}
{-# OPTIONS_HADDOCK show-extensions #-}
-- |
-- Module : Yi.Mode.Haskell
-- License : GPL-2
-- Maintainer : yi-devel@googlegroups.com
-- Stability : experimental
-- Portability : portable
--
-- Collection of 'Mode's for working with Haskell.
module Yi.Mode.Haskell
(
-- * Modes
haskellAbstract,
cleverMode,
preciseMode,
literateMode,
fastMode,
-- * IO-level operations
ghciGet,
ghciSend,
ghciLoadBuffer,
ghciInferType,
ghciSetProcessName,
ghciSetProcessArgs
) where
import Prelude hiding (all, concatMap, elem, error, notElem, exp)
import Lens.Micro.Platform ((&), (.~), (^.))
import Control.Monad (unless, void, when)
import Data.Binary (Binary)
import Data.Default (Default)
import Data.Foldable (all, concatMap, elem, forM_, notElem)
import Data.Maybe (isJust, listToMaybe)
import Data.Monoid ((<>))
import qualified Data.Text as T (any, concat, drop, pack, unpack, unwords)
import Data.Typeable (Typeable)
import Text.Read (readMaybe)
import Yi.Buffer
import Yi.Core (sendToProcess)
import Yi.Debug (error, trace)
import Yi.Editor
import Yi.File (fwriteE)
import qualified Yi.IncrementalParse as IncrParser (State, scanner)
import Yi.Keymap (YiM)
import Yi.Lexer.Alex
import Yi.Lexer.Haskell as Haskell
import qualified Yi.Lexer.LiterateHaskell as LiterateHaskell (HlState, alexScanToken, initState)
import Yi.MiniBuffer (noHint, withMinibufferFree, withMinibufferGen)
import qualified Yi.Mode.GHCi as GHCi (ghciProcessArgs, ghciProcessName, spawnProcess)
import qualified Yi.Mode.Interactive as Interactive (queryReply)
import Yi.Mode.Common (anyExtension, extensionOrContentsMatch, shebangParser)
import Yi.Monad (gets)
import qualified Yi.Rope as R
import Yi.String (fillText, showT)
import Yi.Syntax (ExtHL (..), Scanner, skipScanner)
import qualified Yi.Syntax.Driver as Driver (mkHighlighter)
import Yi.Syntax.Haskell as Hask
import Yi.Syntax.Layout (State)
import Yi.Syntax.OnlineTree as OnlineTree (Tree, manyToks)
import Yi.Syntax.Paren as Paren
import Yi.Syntax.Strokes.Haskell as HS (getStrokes)
import Yi.Syntax.Tree
import Yi.Types (YiVariable)
import Yi.Utils (groupBy')
-- | General ‘template’ for actual Haskell modes.
--
-- It applies over @extensions = ["hs", "x", "hsc", "hsinc"]@ which
-- may be a little questionable but for now Yi is mostly used by
-- Haskell hackers so it should be fine, at least for now.
haskellAbstract :: Mode (tree TT)
haskellAbstract = emptyMode
& modeAppliesA .~ extensionOrContentsMatch extensions (shebangParser "runhaskell")
& modeNameA .~ "haskell"
& modeToggleCommentSelectionA .~ Just (toggleCommentB "--")
where extensions = ["hs", "x", "hsc", "hsinc"]
-- | "Clever" haskell mode, using the paren-matching syntax.
cleverMode :: Mode (Paren.Tree (Tok Haskell.Token))
cleverMode = haskellAbstract
& modeIndentA .~ cleverAutoIndentHaskellB
& modeGetStrokesA .~ strokesOfParenTree
& modeHLA .~ mkParenModeHL (skipScanner 50) haskellLexer
& modeAdjustBlockA .~ adjustBlock
& modePrettifyA .~ cleverPrettify . allToks
fastMode :: Mode (OnlineTree.Tree TT)
fastMode = haskellAbstract
& modeNameA .~ "fast haskell"
& modeHLA .~ mkOnlineModeHL haskellLexer
& modeGetStrokesA .~ tokenBasedStrokes Paren.tokenToStroke
literateMode :: Mode (Paren.Tree TT)
literateMode = haskellAbstract
& modeNameA .~ "literate haskell"
& modeAppliesA .~ anyExtension ["lhs"]
& modeHLA .~ mkParenModeHL id literateHaskellLexer
& modeGetStrokesA .~ strokesOfParenTree
-- FIXME I think that 'begin' should not be ignored
& modeAdjustBlockA .~ adjustBlock
& modeIndentA .~ cleverAutoIndentHaskellB
& modePrettifyA .~ cleverPrettify . allToks
-- | Experimental Haskell mode, using a rather precise parser for the syntax.
preciseMode :: Mode (Hask.Tree TT)
preciseMode = haskellAbstract
& modeNameA .~ "precise haskell"
& modeIndentA .~ cleverAutoIndentHaskellC
& modeGetStrokesA .~ (\ast point begin end -> HS.getStrokes point begin end ast)
& modeHLA .~ mkHaskModeHL haskellLexer
& modePrettifyA .~ cleverPrettify . allToks
--
strokesOfParenTree :: Paren.Tree TT -> Point -> Point -> Point -> [Stroke]
strokesOfParenTree t p b e = Paren.getStrokes p b e t
type CharToTTScanner s = CharScanner -> Scanner (AlexState s) TT
mkParenModeHL :: (IsTree tree, Show state)
=> (Scanner
(IncrParser.State (State Token lexState) TT (Paren.Tree TT))
(Paren.Tree TT)
-> Scanner state (tree (Tok tt)))
-> CharToTTScanner lexState
-> ExtHL (tree (Tok tt))
mkParenModeHL f l = ExtHL $ Driver.mkHighlighter scnr
where
scnr = f . IncrParser.scanner Paren.parse . Paren.indentScanner . l
mkHaskModeHL :: Show st => CharToTTScanner st -> ExtHL (Exp (Tok Token))
mkHaskModeHL l = ExtHL $ Driver.mkHighlighter scnr
where
scnr = IncrParser.scanner Hask.parse . Hask.indentScanner . l
mkOnlineModeHL :: Show st => (CharScanner -> Scanner st (Tok tt))
-> ExtHL (OnlineTree.Tree (Tok tt))
mkOnlineModeHL l = ExtHL $ Driver.mkHighlighter scnr
where
scnr = IncrParser.scanner OnlineTree.manyToks . l
haskellLexer :: CharScanner -> Scanner (AlexState Haskell.HlState) TT
haskellLexer = lexScanner (commonLexer Haskell.alexScanToken Haskell.initState)
literateHaskellLexer :: CharScanner -> Scanner (AlexState LiterateHaskell.HlState) TT
literateHaskellLexer = lexScanner (commonLexer LiterateHaskell.alexScanToken LiterateHaskell.initState)
adjustBlock :: Paren.Tree (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 $ R.replicateChar len ' '
leftN len
else deleteN (negate len)
-- | Returns true if the token should be indented to look as "inside"
-- the group.
insideGroup :: Token -> Bool
insideGroup (Special c) = T.any (== c) "',;})]"
insideGroup _ = True
-- | Helper method for taking information needed for both Haskell auto-indenters:
indentInfoB :: BufferM (Int, Int, Int, Point, Point)
indentInfoB = do
indentLevel <- shiftWidth <$> indentSettingsB
previousIndent <- indentOfB =<< getNextNonBlankLineB Backward
nextIndent <- indentOfB =<< getNextNonBlankLineB Forward
solPnt <- pointAt moveToSol
eolPnt <- pointAt moveToEol
return (indentLevel, previousIndent, nextIndent, solPnt, eolPnt)
cleverAutoIndentHaskellB :: Paren.Tree TT -> IndentBehaviour -> BufferM ()
cleverAutoIndentHaskellB e behaviour = do
(indentLevel, previousIndent, nextIndent, solPnt, eolPnt) <- indentInfoB
let onThisLine ofs = ofs >= solPnt && ofs <= eolPnt
firstTokNotOnLine = listToMaybe .
filter (not . onThisLine . posnOfs . tokPosn) .
filter (not . isErrorTok . tokT) . concatMap 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 (_: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
groupIndent (Tok {}) _ = error "unable to indent code"
case getLastPath [e] solPnt of
Nothing -> return ()
Just path -> let stops = stopsOf path
in trace ("Stops = " <> showT stops) $
trace ("firstTokOnLine = " <> showT firstTokOnLine) $
cycleIndentsB behaviour stops
cleverAutoIndentHaskellC :: Exp TT -> IndentBehaviour -> BufferM ()
cleverAutoIndentHaskellC e behaviour = do
(indentLevel, previousIndent, nextIndent, solPnt, eolPnt) <- indentInfoB
let onThisLine ofs = ofs >= solPnt && ofs <= eolPnt
firstTokNotOnLine = listToMaybe .
filter (not . onThisLine . posnOfs . tokPosn) .
filter (not . isErrorTok . tokT) . concatMap allToks
let stopsOf :: [Hask.Exp TT] -> [Int]
stopsOf (g@(Hask.Paren (Hask.PAtom open _) ctnt (Hask.PAtom 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 (Hask.PAtom (Tok {tokT = t}) _:_) | startsLayout t || (t == ReservedOp Equal)
= [nextIndent, previousIndent + indentLevel]
-- of; where; etc. ends the previous line. 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 (l@(Hask.PLet _ (Hask.Block _) _):ts') = [colOf' l | lineStartsWith (Reserved Haskell.In)] <> stopsOf ts'
-- offer to align with let only if this is an "in"
stopsOf (t@(Hask.Block _):ts') = (shiftBlock + colOf' t) : stopsOf ts'
-- offer add another statement in the block
stopsOf (Hask.PGuard' (PAtom pipe _) _ _:ts') = [tokCol pipe | lineStartsWith (ReservedOp Haskell.Pipe)] <> stopsOf ts'
-- offer to align against another guard
stopsOf (d@(Hask.PData {}):ts') = colOf' d + indentLevel
: stopsOf ts' --FIXME!
stopsOf (Hask.RHS (Hask.PAtom{}) exp:ts')
= [case firstTokOnLine of
Just (Operator op') -> opLength op' (colOf' exp) -- Usually operators are aligned against the '=' sign
-- case of an operator should check so that value always is at least 1
_ -> colOf' exp | lineIsExpression ] <> stopsOf ts'
-- offer to continue the RHS if this looks like an expression.
stopsOf [] = [0] -- maybe it's new declaration in the module
stopsOf (_:ts) = stopsOf ts -- by default, there is no reason to indent against an expression.
-- calculate indentation of operator (must be at least 1 to be valid)
opLength ts' r = let l = r - (length ts' + 1) -- I find this dubious...
in if l > 0 then l else 1
lineStartsWith tok = firstTokOnLine == Just tok
lineIsExpression = all (`notElem` [ReservedOp Haskell.Pipe, ReservedOp Haskell.Equal, ReservedOp RightArrow]) toksOnLine
&& not (lineStartsWith (Reserved Haskell.In))
-- TODO: check the tree instead of guessing by looking at tokens
firstTokOnLine = listToMaybe toksOnLine
toksOnLine = fmap tokT $
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
groupIndent (Tok{}) _ = error "unable to indent code"
case getLastPath [e] solPnt of
Nothing -> return ()
Just path ->let stops = stopsOf path
in trace ("Path = " <> showT path) $
trace ("Stops = " <> showT stops) $
trace ("Previous indent = " <> showT previousIndent) $
trace ("Next indent = " <> showT nextIndent) $
trace ("firstTokOnLine = " <> showT firstTokOnLine) $
cycleIndentsB behaviour stops
colOf' :: Foldable t => t TT -> Int
colOf' = maybe 0 tokCol . getFirstElement
tokCol :: Tok t -> Int
tokCol = posnCol . tokPosn
nominalIndent :: Char -> Int
nominalIndent '{' = 2
nominalIndent _ = 1
tokText :: Tok t -> BufferM R.YiString
tokText = readRegionB . tokRegion
tokRegion :: Tok t -> Region
tokRegion t = mkRegion (tokBegin t) (tokEnd t)
isLineComment :: TT -> Bool
isLineComment = (Just Haskell.Line ==) . tokTyp . tokT
contiguous :: 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 :: [TT] -> BufferM ()
cleverPrettify toks = do
pnt <- pointB
let 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
text <- T.unwords . fmap (T.drop 2 . R.toText) <$> mapM tokText g
let region = mkRegion (tokBegin . head $ g) (tokEnd . last $ g)
mkGrp = const . R.unlines $ R.append "-- " <$> fillText 80 (R.fromText text)
modifyRegionB mkGrp region
tokTyp :: Token -> Maybe Haskell.CommentType
tokTyp (Comment t) = Just t
tokTyp _ = Nothing
-- TODO: export or remove
-- -- 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
-- | Variable storing the possibe buffer reference where GHCi is
-- currently running.
newtype GhciBuffer = GhciBuffer {_ghciBuffer :: Maybe BufferRef}
deriving (Default, Typeable, Binary)
instance YiVariable GhciBuffer
-- | Start GHCi in a buffer
ghci :: YiM BufferRef
ghci = do
g <- getEditorDyn
b <- GHCi.spawnProcess (g ^. GHCi.ghciProcessName) (g ^. GHCi.ghciProcessArgs)
withEditor . putEditorDyn . 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 getEditorDyn
case mb of
Nothing -> ghci
Just b -> do
stillExists <- 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
void fwriteE
f <- withCurrentBuffer (gets file)
case f of
Nothing -> error "Couldn't get buffer filename in ghciLoadBuffer"
Just filename -> ghciSend $ ":load " <> show filename
-- Tells ghci to infer the type of the identifier at point. Doesn't
-- check for errors (yet)
ghciInferType :: YiM ()
ghciInferType = do
nm <- withCurrentBuffer (readUnitB unitWord)
unless (R.null nm) $
withMinibufferGen (R.toText nm) noHint "Insert type of which identifier?"
return (const $ return ()) (ghciInferTypeOf . R.fromText)
ghciInferTypeOf :: R.YiString -> YiM ()
ghciInferTypeOf nm = do
buf <- ghciGet
result <- Interactive.queryReply buf (":t " <> R.toString nm)
let successful = (not . R.null) nm && nm == result
when successful . withCurrentBuffer $
moveToSol *> insertB '\n' *> leftB
*> insertN result *> rightB
ghciSetProcessName :: YiM ()
ghciSetProcessName = do
g <- getEditorDyn
let nm = g ^. GHCi.ghciProcessName
prompt = T.concat [ "Command to call for GHCi, currently ‘"
, T.pack nm, "’: " ]
withMinibufferFree prompt $ \s ->
putEditorDyn $ g & GHCi.ghciProcessName .~ T.unpack s
ghciSetProcessArgs :: YiM ()
ghciSetProcessArgs = do
g <- getEditorDyn
let nm = g ^. GHCi.ghciProcessName
args = g ^. GHCi.ghciProcessArgs
prompt = T.unwords [ "List of args to call "
, T.pack nm
, "with, currently"
, T.pack $ show args
, ":"
]
withMinibufferFree prompt $ \arg ->
case readMaybe $ T.unpack arg of
Nothing -> printMsg "Could not parse as [String], keep old args."
Just arg' -> putEditorDyn $ g & GHCi.ghciProcessArgs .~ arg'