alex.hsinc

-- -*- Haskell -*-

-- The include file for alex-generated syntax highlighters.  Because alex
-- declares its own types, any wrapper must have the highlighter in scope...
-- so it must be included.  Doubleplusyuck.

-- | Scan one token. Return (maybe) a token and a new state.
alexScanToken :: (AlexState HlState, AlexInput) -> Maybe (Tok Token, (AlexState HlState, AlexInput))
alexScanToken (AlexState state lookedOfs pos, inp) = 
    let (scn,lookahead) = alexScan' inp (stateToInit state) 
        lookedOfs' = max lookedOfs (posnOfs pos +~ Size lookahead) in
    case scn of
		AlexEOF -> Nothing
		AlexError _ -> error "lexical error"
		AlexSkip  inp' len  -> 
                    let chunk = take (fromIntegral len) inp
                    in alexScanToken (AlexState state lookedOfs' (moveStr pos chunk), inp')
		AlexToken inp' len act -> 
                    let (state', style) = act chunk state 
                        chunk = take (fromIntegral len) inp
                        newPos = moveStr pos chunk
                    in Just (Tok style (posnOfs newPos ~- posnOfs pos) pos, (AlexState state' lookedOfs' newPos, inp'))

alexScan' input (I# (sc))
  = alexScanUser' undefined input (I# (sc))

alexScanUser' user input (I# (sc))
  = case alex_scan_tkn' user input 0# input sc AlexNone of
	(AlexNone, input', lookahead) ->
		case alexGetChar input of
			Nothing -> (AlexEOF, lookahead)
			Just _  -> (AlexError input', lookahead)
	(AlexLastSkip input len, _, lookahead) -> (AlexSkip input len, lookahead)
	(AlexLastAcc k input len, _, lookahead) -> (AlexToken input len k, lookahead)


-- Same as alex_scan_tkn, but also return the length of lookahead.
alex_scan_tkn' user orig_input len input s last_acc =
  input `seq` -- strict in the input
  let 
	new_acc = check_accs (alex_accept `quickIndex` (I# (s)))
  in
  new_acc `seq`
  case alexGetChar input of
     Nothing -> (new_acc, input, I# len)
     Just (c, new_input) -> 



	let
		base   = alexIndexInt32OffAddr alex_base s
		(I# (ord_c)) = ord c
		offset = (base +# ord_c)
		check  = alexIndexInt16OffAddr alex_check offset
		
		new_s = if (offset >=# 0#) && (check ==# ord_c)
			  then alexIndexInt16OffAddr alex_table offset
			  else alexIndexInt16OffAddr alex_deflt s
                new_len = len +# 1#
	in
	case new_s of 
	    -1# -> (new_acc, input, I# new_len)
		-- on an error, we want to keep the input *before* the
		-- character that failed, not after.
                -- (but still, we looked after)
    	    _ -> alex_scan_tkn' user orig_input new_len
			new_input new_s new_acc

  where
	check_accs [] = last_acc
	check_accs (AlexAcc a : _) = AlexLastAcc a input (I# (len))
	check_accs (AlexAccSkip : _)  = AlexLastSkip  input (I# (len))
	check_accs (AlexAccPred a pred : rest)
	   | pred user orig_input (I# (len)) input
	   = AlexLastAcc a input (I# (len))
	check_accs (AlexAccSkipPred pred : rest)
	   | pred user orig_input (I# (len)) input
	   = AlexLastSkip input (I# (len))
	check_accs (_ : rest) = check_accs rest

c = actionConst
m = actionAndModify