Fix loose parser not making sure endOfInput is reached; add two families of operators and simplify the «Show» instance with a dedicated function to allow deleting lines of uninteresting code

This commit is contained in:
Tissevert 2020-02-06 16:54:27 +01:00
parent 3f6b0651f3
commit 57996749c6

View file

@ -13,7 +13,8 @@ import Control.Monad.Reader (ReaderT, runReaderT, asks)
import Control.Monad.State (MonadState, evalStateT, get, modify, put)
import Data.Attoparsec.ByteString.Char8 (choice, sepBy)
import Data.ByteString (ByteString)
import Data.ByteString.Char8 (pack)
import Data.ByteString.Char8 (pack, unpack)
import Data.Char (toLower)
import Data.Map ((!), (!?), Map)
import qualified Data.Map as Map (fromList)
import PDF.Font (Font, FontSet, emptyFont)
@ -21,22 +22,43 @@ import PDF.Object (
DirectObject(..), StringObject(..)
, array, blank, name, regular, stringObject, toByteString
)
import PDF.Parser (MonadParser, (<?>), Parser, evalParser, string, takeAll1)
import PDF.Parser (MonadParser(..), (<?>), Parser, evalParser)
data StateOperator =
Cm | W | J | J_ | M | D | Ri | I | Gs -- general graphic state
deriving (Bounded, Enum)
C_m | W_ | J | J_ | M | D_ | R_i | I_ | G_s -- general graphic state
deriving (Bounded, Enum, Show)
data PathOperator =
M_ | L_ | C_ | V_ | Y_ | H_ | R_e -- path construction
| S | S_ | F_ | F | Fstar | B | Bstar | B_ | B_star | N_ -- path painting
| W | Wstar -- clipping path
deriving (Bounded, Enum, Show)
data ColorOperator =
CS | C_s | SC | SCN | S_c | S_cn | G | G_ | RG | R_g | K | K_
deriving (Bounded, Enum, Show)
data TextOperator =
Td | TD | Tm | Tstar -- text positioning
| TJ | Tj | Quote | DQuote -- text showing
| Tc | Tw | Tz | TL | Tf | Tr | Ts -- text state
deriving (Bounded, Enum)
deriving (Bounded, Enum, Show)
data Argument = Raw ByteString | Typed DirectObject deriving Show
type Call a = (a, [Argument])
type Operator a = (Bounded a, Enum a, Show a)
code :: Operator a => a -> ByteString
code = pack . expand . show
where
expand "" = ""
expand (c:'_':s) = toLower c : expand s
expand ('s':'t':'a':'r':s) = '*' : expand s
expand ('Q':'u':'o':'t':'e':s) = '\'' : expand s
expand ('D':'Q':'u':'o':'t':'e':s) = '"' : expand s
expand (c:s) = c : expand s
{-
instance Show StateOperator where
show Cm = "cm"
show W = "w"
show W_ = "w"
show J = "J"
show J_ = "j"
show M = "M"
@ -45,6 +67,35 @@ instance Show StateOperator where
show I = "i"
show Gs = "gs"
instance Show PathOperator where
show M_ = "m"
show L_ = "l"
show C_ = "c"
show V_ = "v"
show Y_ = "y"
show H_
("m", (M_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False))
, ("l", (L_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False))
, ("c", (L_, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("v", (L_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("y", (L_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("h", (L_, \l -> case l of [] -> True ; _ -> False))
, ("re", (L_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("S", (L_, \l -> case l of [] -> True ; _ -> False))
, ("s", (L_, \l -> case l of [] -> True ; _ -> False))
, ("f", (L_, \l -> case l of [] -> True ; _ -> False))
, ("F", (L_, \l -> case l of [] -> True ; _ -> False))
, ("F*", (L_, \l -> case l of [] -> True ; _ -> False))
, ("B", (L_, \l -> case l of [] -> True ; _ -> False))
, ("B*", (L_, \l -> case l of [] -> True ; _ -> False))
, ("b", (L_, \l -> case l of [] -> True ; _ -> False))
, ("b*", (L_, \l -> case l of [] -> True ; _ -> False))
, ("n", (L_, \l -> case l of [] -> True ; _ -> False))
, ("W", (L_, \l -> case l of [] -> True ; _ -> False))
, ("W*", (L_, \l -> case l of [] -> True ; _ -> False))
instance Show ColorOperator where
instance Show TextOperator where
show Td = "Td"
show TD = "TD"
@ -61,18 +112,58 @@ instance Show TextOperator where
show Tf = "Tf"
show Tr = "Tr"
show Ts = "Ts"
-}
stateOperator :: OperatorTable StateOperator
stateOperator = Map.fromList [
("cm", (Cm, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False))
, ("w", (W, \l -> case l of [Raw _] -> True ; _ -> False))
, ("J", (J, \l -> case l of [Raw _] -> True ; _ -> False))
, ("j", (J_, \l -> case l of [Raw _] -> True ; _ -> False))
, ("M", (M, \l -> case l of [Raw _] -> True ; _ -> False))
, ("d", (D, \l -> case l of [Raw _, Raw _] -> True ; _ -> False))
, ("ri", (Ri, \l -> case l of [Raw _] -> True ; _ -> False))
, ("i", (I, \l -> case l of [Raw _] -> True ; _ -> False))
, ("gs", (Gs, \l -> case l of [Typed (NameObject _)] -> True ; _ -> False))
stateOperator = Map.fromList $ (\(op, checker) -> (code op, (op, checker))) <$> [
(C_m, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (W_, \l -> case l of [Raw _] -> True ; _ -> False)
, (J, \l -> case l of [Raw _] -> True ; _ -> False)
, (J_, \l -> case l of [Raw _] -> True ; _ -> False)
, (M, \l -> case l of [Raw _] -> True ; _ -> False)
, (D_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (R_i, \l -> case l of [Raw _] -> True ; _ -> False)
, (I_, \l -> case l of [Raw _] -> True ; _ -> False)
, (G_s, \l -> case l of [Typed (NameObject _)] -> True ; _ -> False)
]
pathOperator :: OperatorTable PathOperator
pathOperator = Map.fromList $ (\(op, checker) -> (code op, (op, checker))) <$> [
(M_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (L_, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (C_, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (V_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (Y_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (H_, \l -> case l of [] -> True ; _ -> False)
, (R_e, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (S, \l -> case l of [] -> True ; _ -> False)
, (S_, \l -> case l of [] -> True ; _ -> False)
, (F_, \l -> case l of [] -> True ; _ -> False)
, (F, \l -> case l of [] -> True ; _ -> False)
, (Fstar, \l -> case l of [] -> True ; _ -> False)
, (B, \l -> case l of [] -> True ; _ -> False)
, (Bstar, \l -> case l of [] -> True ; _ -> False)
, (B_, \l -> case l of [] -> True ; _ -> False)
, (B_star, \l -> case l of [] -> True ; _ -> False)
, (N_, \l -> case l of [] -> True ; _ -> False)
, (W, \l -> case l of [] -> True ; _ -> False)
, (Wstar, \l -> case l of [] -> True ; _ -> False)
]
colorOperator :: OperatorTable ColorOperator
colorOperator = Map.fromList $ (\(op, checker) -> (code op, (op, checker))) <$> [
(CS, \l -> case l of [Typed (NameObject _)] -> True ; _ -> False)
, (C_s, \l -> case l of [Typed (NameObject _)] -> True ; _ -> False)
, (SC, \_ -> True)
, (SCN, \_ -> True)
, (S_c, \_ -> True)
, (S_cn, \_ -> True)
, (G, \l -> case l of [Raw _] -> True ; _ -> False)
, (G_, \l -> case l of [Raw _] -> True ; _ -> False)
, (RG, \l -> case l of [Raw _, Raw _, Raw _] -> True ; _ -> False)
, (R_g, \l -> case l of [Raw _, Raw _, Raw _] -> True ; _ -> False)
, (K, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
, (K_, \l -> case l of [Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
]
{-
@ -89,7 +180,7 @@ stateOperator _ = False
-}
textOperator :: OperatorTable TextOperator
textOperator = Map.fromList $ (\(op, checker) -> (pack $ show op, (op, checker))) <$> [
textOperator = Map.fromList $ (\(op, checker) -> (code op, (op, checker))) <$> [
(Td, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (TD, \l -> case l of [Raw _, Raw _] -> True ; _ -> False)
, (Tm, \l -> case l of [Raw _, Raw _, Raw _, Raw _, Raw _, Raw _] -> True ; _ -> False)
@ -127,7 +218,7 @@ textOperator _ = False
-}
type ArgumentStackParser m = (MonadState [Argument] m, MonadParser m)
type Operator a = (Bounded a, Enum a, Show a)
--type Operator a = (Bounded a, Enum a, Show a)
type OperatorTable a = Map ByteString (TypeChecker a)
type TypeChecker a = (a, [Argument] -> Bool)
@ -146,14 +237,14 @@ callChunk table =
Nothing -> return . Right $ Raw chunk
Just typeChecker -> return $ Left typeChecker
stackParser :: (ArgumentStackParser m, Show a) => OperatorTable a -> m (Call a)
stackParser :: (ArgumentStackParser m, Operator a) => OperatorTable a -> m (Call a)
stackParser table = either popCall push =<< (callChunk table)
where
push arg = modify (arg:) >> stackParser table
popCall (operator, predicate) = do
arguments <- reverse <$> get
let call = (operator, arguments)
if predicate arguments then return call else fail (show call)
if predicate arguments then return call else fail (unpack $ code operator)
a :: (Operator a, MonadParser m) => OperatorTable a -> m (Call a)
a table = evalStateT (stackParser table) []
@ -173,24 +264,29 @@ stringArg = Typed . StringObject <$> stringObject <* blank
type ParserWithFont = ReaderT FontSet (Parser Font)
pageContents :: FontSet -> ByteString -> Either String [ByteString]
pageContents font input =
evalParser (runReaderT page font) emptyFont input
pageContents fontSet input =
evalParser (runReaderT (page) fontSet) emptyFont input
several :: MonadParser m => m [a] -> m [a]
several p = concat <$> (p `sepBy` blank)
page :: ParserWithFont [ByteString]
page = graphicState <|> text <?> "Text page contents"
page = several (graphicState <|> text) <* blank <* endOfInput <?> "Text page contents"
graphicState :: ParserWithFont [ByteString]
graphicState =
(string "q" *> blank *> insideQ <* blank <* string "Q") <?> "Graphic state"
string "q" *> blank *> insideQ <* blank <* string "Q" <?> "Graphic state"
where
insideQ = concat <$> ((command <|> page) `sepBy` blank )
command = a stateOperator *> return []
insideQ = several (command <|> graphicState <|> text)
ignore x = a x *> return []
command =
ignore stateOperator <|> ignore pathOperator <|> ignore colorOperator
text :: ParserWithFont [ByteString]
text =
string "BT" *> blank *> commands <* blank <* string "ET" <?> "Text operators"
where
commands = concat <$> (a textOperator >>= runOperator) `sepBy` blank
commands = several (a textOperator >>= runOperator)
runOperator :: Call TextOperator -> ParserWithFont [ByteString]
runOperator (Tf, [Typed (NameObject fontName), _]) =