illuminate-0.1: alex/AlexWrapper-illuminate
import Text.Highlighting.Illuminate.Types
import Data.Sequence (Seq, (><), (<|), (|>), singleton, viewl, ViewL(..))
import qualified Data.Sequence as Seq (empty)
import qualified Data.Foldable as F
import Data.List (span, break, splitAt, isPrefixOf)
{-# LINE 1 "templates/wrappers.hs" #-}
{-# LINE 1 "templates/wrappers.hs" #-}
{-# LINE 1 "<built-in>" #-}
{-# LINE 1 "<command line>" #-}
{-# LINE 1 "templates/wrappers.hs" #-}
-- -----------------------------------------------------------------------------
-- Alex wrapper code.
--
-- This code is in the PUBLIC DOMAIN; you may copy it freely and use
-- it for any purpose whatsoever.
{-# LINE 18 "templates/wrappers.hs" #-}
-- -----------------------------------------------------------------------------
-- The input type
type AlexInput = (AlexPosn, -- current position,
Char, -- previous char
String) -- current input string
alexInputPrevChar :: AlexInput -> Char
alexInputPrevChar (p,c,s) = c
alexGetChar :: AlexInput -> Maybe (Char,AlexInput)
alexGetChar (p,c,[]) = Nothing
alexGetChar (p,_,(c:s)) = let p' = alexMove p c in p' `seq`
Just (c, (p', c, s))
{-# LINE 51 "templates/wrappers.hs" #-}
-- -----------------------------------------------------------------------------
-- Token positions
-- `Posn' records the location of a token in the input text. It has three
-- fields: the address (number of chacaters preceding the token), line number
-- and column of a token within the file. `start_pos' gives the position of the
-- start of the file and `eof_pos' a standard encoding for the end of file.
-- `move_pos' calculates the new position after traversing a given character,
-- assuming the usual eight character tab stops.
data AlexPosn = AlexPn !Int !Int !Int
deriving (Eq,Show)
alexStartPos :: AlexPosn
alexStartPos = AlexPn 0 1 1
alexMove :: AlexPosn -> Char -> AlexPosn
alexMove (AlexPn a l c) '\t' = AlexPn (a+1) l (((c+7) `div` 8)*8+1)
alexMove (AlexPn a l c) '\n' = AlexPn (a+1) (l+1) 1
alexMove (AlexPn a l c) _ = AlexPn (a+1) l (c+1)
-- -----------------------------------------------------------------------------
-- Default monad
data AlexState = AlexState {
alex_pos :: !AlexPosn, -- position at current input location
alex_inp :: String, -- the current input
alex_chr :: !Char, -- the character before the input
alex_scd :: !Int -- the current startcode
, alex_ust :: AlexUserState -- AlexUserState will be defined in the user program
}
-- Compile with -funbox-strict-fields for best results!
runAlex :: String -> Alex a -> Either String a
runAlex input (Alex f)
= case f (AlexState {alex_pos = alexStartPos,
alex_inp = input,
alex_chr = '\n',
alex_ust = alexInitUserState,
alex_scd = 0}) of Left msg -> Left msg
Right ( _, a ) -> Right a
newtype Alex a = Alex { unAlex :: AlexState -> Either String (AlexState, a) }
instance Monad Alex where
m >>= k = Alex $ \s -> case unAlex m s of
Left msg -> Left msg
Right (s',a) -> unAlex (k a) s'
return a = Alex $ \s -> Right (s,a)
alexGetInput :: Alex AlexInput
alexGetInput
= Alex $ \s@AlexState{alex_pos=pos,alex_chr=c,alex_inp=inp} ->
Right (s, (pos,c,inp))
alexSetInput :: AlexInput -> Alex ()
alexSetInput (pos,c,inp)
= Alex $ \s -> case s{alex_pos=pos,alex_chr=c,alex_inp=inp} of
s@(AlexState{}) -> Right (s, ())
alexError :: String -> Alex a
alexError message = Alex $ \s -> Left message
alexGetStartCode :: Alex Int
alexGetStartCode = Alex $ \s@AlexState{alex_scd=sc} -> Right (s, sc)
alexSetStartCode :: Int -> Alex ()
alexSetStartCode sc = Alex $ \s -> Right (s{alex_scd=sc}, ())
alexMonadScan = do
inp <- alexGetInput
sc <- alexGetStartCode
case alexScan inp sc of
AlexEOF -> alexEOF
AlexError inp' -> alexError "lexical error"
AlexSkip inp' len -> do
alexSetInput inp'
alexMonadScan
AlexToken inp' len action -> do
alexSetInput inp'
action inp len
-- -----------------------------------------------------------------------------
-- Useful token actions
type AlexAction result = AlexInput -> Int -> result
-- just ignore this token and scan another one
-- skip :: AlexAction result
skip input len = alexMonadScan
-- ignore this token, but set the start code to a new value
-- begin :: Int -> AlexAction result
begin code input len = do alexSetStartCode code; alexMonadScan
-- perform an action for this token, and set the start code to a new value
-- andBegin :: AlexAction result -> Int -> AlexAction result
(action `andBegin` code) input len = do alexSetStartCode code; action input len
-- token :: (String -> Int -> token) -> AlexAction token
token t input len = return (t input len)
-- -----------------------------------------------------------------------------
-- Monad (with ByteString input)
{-# LINE 251 "templates/wrappers.hs" #-}
-- -----------------------------------------------------------------------------
-- Basic wrapper
{-# LINE 273 "templates/wrappers.hs" #-}
-- -----------------------------------------------------------------------------
-- Basic wrapper, ByteString version
{-# LINE 297 "templates/wrappers.hs" #-}
{-# LINE 322 "templates/wrappers.hs" #-}
-- -----------------------------------------------------------------------------
-- Posn wrapper
-- Adds text positions to the basic model.
{-# LINE 339 "templates/wrappers.hs" #-}
-- -----------------------------------------------------------------------------
-- Posn wrapper, ByteString version
{-# LINE 354 "templates/wrappers.hs" #-}
-- -----------------------------------------------------------------------------
-- GScan wrapper
-- For compatibility with previous versions of Alex, and because we can.
-- -----------------------------------------------------------------------------
-- Custom code for highlighting
alexEOF = return $ singleton (EOF,"")
type AlexUserState = [(Int,TokenType)] -- a stack of codes and default token types
alexInitUserState = [(0,Plain)]
tok :: TokenType -> AlexInput -> Int -> Alex Tokens
tok t (_,_,s) len = return $ singleton (t, take len s)
getUserState :: Alex AlexUserState
getUserState = Alex $ \s@AlexState{alex_ust=ust} -> Right (s, ust)
setUserState :: AlexUserState -> Alex ()
setUserState newstate = Alex $ \s -> Right (s{alex_ust=newstate}, ())
modifyUserState :: (AlexUserState -> AlexUserState) -> Alex ()
modifyUserState fn = Alex $ \s@AlexState{alex_ust=ust} -> Right (s{alex_ust = fn ust}, ())
plain :: AlexInput -> Int -> Alex Tokens
plain (_,_,s) len = do
((_,defaultToken) : _) <- getUserState
return $ singleton (defaultToken, take len s)
pushContext :: (Int, TokenType) -> b -> Alex b
pushContext newcontext toks = do
modifyUserState (newcontext :)
alexSetStartCode $ fst newcontext
return toks
popContext :: b -> Alex b
popContext toks = do
contexts <- getUserState
case contexts of
[] -> error "Empty contexts stack!"
[x] -> return toks
(x:y:xs) -> do
setUserState (y:xs)
alexSetStartCode $ fst y
return toks
scanForStop :: String -> String -> Int
scanForStop stop ('\n':xs) = 1 +
let (sps, xs') = span (`elem` " \t") xs
offset = length sps + length stop
in if stop `isPrefixOf` xs'
then case (takeWhile (`elem` " \t") $ drop (length stop) xs') of
('\n':_) -> offset
[] -> offset
_ -> offset + scanForStop stop (drop offset xs')
else length sps + scanForStop stop xs'
scanForStop stop (_:xs) = 1 + scanForStop stop xs
scanForStop stop [] = 0
hereDoc :: Tokens -> Alex Tokens
hereDoc toks = Alex $ \s ->
let inp = alex_inp s
unescape ('\\':x:xs) = x : unescape xs
unescape (x:xs) = x : unescape xs
unescape [] = []
unstring = tail . init . unescape
in case viewl toks of
((tt,str) :< empty) | tt `elem` [String, VarId] ->
let stop = if tt == String then unstring str else str
off = scanForStop stop inp
(res, newinp) = splitAt off inp
newpos = foldl alexMove (alex_pos s) res
s' = s{alex_pos = newpos, alex_inp = newinp, alex_chr = '\n'}
in Right (s', toks |> (String, res))
_ -> Left "hereDoc expecting String or VarId"
(==>) :: (AlexInput -> Int -> Alex a) -> (a -> Alex b) -> (AlexInput -> Int -> Alex b)
(act1 ==> act2) inp len = do
res <- act1 inp len
act2 res
scanner :: Scanner
scanner str = runAlex str $ do
let loop acc = do toks <- alexMonadScan
case viewl toks of
((t,_) :< _) | t == EOF -> return acc
_ -> loop (acc >< toks)
loop Seq.empty
tokenizeWith :: Lexer -> AlexInput -> Int -> Alex Tokens
tokenizeWith lx (_,_,s) len = do
case (scan lx) (take len s) of
Left e -> fail e
Right r -> return r
scanWith :: Lexer -> Tokens -> Alex Tokens
scanWith lx toks = Alex $ \s ->
case (scan lx) (alex_inp s) of
Left e -> Left e
Right r -> Right (s', toks >< r)
where s' = s{alex_pos = newpos, alex_inp = newinp, alex_chr = lastchar}
parsed_chars = F.concatMap snd r
newpos = foldl alexMove (alex_pos s) parsed_chars
lastchar = if null parsed_chars then '\n' else last parsed_chars
newinp = drop (length parsed_chars) (alex_inp s)