alex-3.2.6: data/AlexTemplate

{-# LINE 1 "templates/GenericTemplate.hs" #-}
-- -----------------------------------------------------------------------------
-- ALEX TEMPLATE
--
-- This code is in the PUBLIC DOMAIN; you may copy it freely and use
-- it for any purpose whatsoever.

-- -----------------------------------------------------------------------------
-- INTERNALS and main scanner engine




































































alexIndexInt16OffAddr arr off = arr ! off
























alexIndexInt32OffAddr arr off = arr ! off











quickIndex arr i = arr ! i


-- -----------------------------------------------------------------------------
-- Main lexing routines

data AlexReturn a
  = AlexEOF
  | AlexError  !AlexInput
  | AlexSkip   !AlexInput !Int
  | AlexToken  !AlexInput !Int a

-- alexScan :: AlexInput -> StartCode -> AlexReturn a
alexScan input__ (sc)
  = alexScanUser undefined input__ (sc)

alexScanUser user__ input__ (sc)
  = case alex_scan_tkn user__ input__ (0) input__ sc AlexNone of
  (AlexNone, input__') ->
    case alexGetByte input__ of
      Nothing ->



                                   AlexEOF
      Just _ ->



                                   AlexError input__'

  (AlexLastSkip input__'' len, _) ->



    AlexSkip input__'' len

  (AlexLastAcc k input__''' len, _) ->



    AlexToken input__''' len (alex_actions ! k)


-- Push the input through the DFA, remembering the most recent accepting
-- state it encountered.

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` (s)))
  in
  new_acc `seq`
  case alexGetByte input__ of
     Nothing -> (new_acc, input__)
     Just (c, new_input) ->



      case fromIntegral c of { (ord_c) ->
        let
                base   = alexIndexInt32OffAddr alex_base s
                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
        in
        case new_s of
            (-1) -> (new_acc, input__)
                -- on an error, we want to keep the input *before* the
                -- character that failed, not after.
            _ -> alex_scan_tkn user__ orig_input (if c < 0x80 || c >= 0xC0 then (len + (1)) else len)
                                                -- note that the length is increased ONLY if this is the 1st byte in a char encoding)
                        new_input new_s new_acc
      }
  where
        check_accs (AlexAccNone) = last_acc
        check_accs (AlexAcc a  ) = AlexLastAcc a input__ (len)
        check_accs (AlexAccSkip) = AlexLastSkip  input__ (len)

        check_accs (AlexAccPred a predx rest)
           | predx user__ orig_input (len) input__
           = AlexLastAcc a input__ (len)
           | otherwise
           = check_accs rest
        check_accs (AlexAccSkipPred predx rest)
           | predx user__ orig_input (len) input__
           = AlexLastSkip input__ (len)
           | otherwise
           = check_accs rest


data AlexLastAcc
  = AlexNone
  | AlexLastAcc !Int !AlexInput !Int
  | AlexLastSkip     !AlexInput !Int

data AlexAcc user
  = AlexAccNone
  | AlexAcc Int
  | AlexAccSkip

  | AlexAccPred Int (AlexAccPred user) (AlexAcc user)
  | AlexAccSkipPred (AlexAccPred user) (AlexAcc user)

type AlexAccPred user = user -> AlexInput -> Int -> AlexInput -> Bool

-- -----------------------------------------------------------------------------
-- Predicates on a rule

alexAndPred p1 p2 user__ in1 len in2
  = p1 user__ in1 len in2 && p2 user__ in1 len in2

--alexPrevCharIsPred :: Char -> AlexAccPred _
alexPrevCharIs c _ input__ _ _ = c == alexInputPrevChar input__

alexPrevCharMatches f _ input__ _ _ = f (alexInputPrevChar input__)

--alexPrevCharIsOneOfPred :: Array Char Bool -> AlexAccPred _
alexPrevCharIsOneOf arr _ input__ _ _ = arr ! alexInputPrevChar input__

--alexRightContext :: Int -> AlexAccPred _
alexRightContext (sc) user__ _ _ input__ =
     case alex_scan_tkn user__ input__ (0) input__ sc AlexNone of
          (AlexNone, _) -> False
          _ -> True
        -- TODO: there's no need to find the longest
        -- match when checking the right context, just
        -- the first match will do.