6528082 · typeable/pandoc

git.iko.soy/typeable/pandoc

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Lua filters: improve error messages

6528082Albert Krewinkel9 years ago

pandoc.cabal+1

compare with master

unifiedsplit

@@ -347,6 +347,7 @@ library

347 unordered-containers >= 0.2 && < 0.3,

348 parsec >= 3.1 && < 3.2,

349 mtl >= 2.2 && < 2.3,

350+ exceptions >= 0.8 && < 0.9,

350 filepath >= 1.1 && < 1.5,

351 filepath >= 1.1 && < 1.5,

351 process >= 1.2.3 && < 1.7,

352 process >= 1.2.3 && < 1.7,

352 directory >= 1 && < 1.4,

353 directory >= 1 && < 1.4,

src/Text/Pandoc/Lua/Filter.hs+6−2

@@ -11,6 +11,7 @@ module Text.Pandoc.Lua.Filter ( LuaFilterFunction

11 , inlineElementNames

12 ) where

13import Control.Monad (mplus, unless, when, (>=>))

14+import Control.Monad.Catch (finally)

14import Text.Pandoc.Definition

15import Text.Pandoc.Definition

15import Data.Foldable (foldrM)

16import Data.Foldable (foldrM)

16import Data.Map (Map)

17import Data.Map (Map)

@@ -22,6 +23,7 @@ import Text.Pandoc.Walk (walkM, Walkable)

22import Data.Data (Data, DataType, dataTypeConstrs, dataTypeName, dataTypeOf,

23import Data.Data (Data, DataType, dataTypeConstrs, dataTypeName, dataTypeOf,

23 showConstr, toConstr, tyconUQname)

24 showConstr, toConstr, tyconUQname)

24import Text.Pandoc.Lua.StackInstances()

25import Text.Pandoc.Lua.StackInstances()

26+import Text.Pandoc.Lua.Util (typeCheck)

26type FunctionMap = Map String LuaFilterFunction

28type FunctionMap = Map String LuaFilterFunction

@@ -65,7 +67,7 @@ registerFilterFunction idx = do

66elementOrList :: FromLuaStack a => a -> Lua [a]

68elementOrList :: FromLuaStack a => a -> Lua [a]

67elementOrList x = do

69elementOrList x = do

68− let topOfStack = Lua.StackIndex (-1)

70+ let topOfStack = Lua.stackTop

69 elementUnchanged <- Lua.isnil topOfStack

71 elementUnchanged <- Lua.isnil topOfStack

70 if elementUnchanged

72 if elementUnchanged

71 then [x] <$ Lua.pop 1

73 then [x] <$ Lua.pop 1

@@ -73,7 +75,9 @@ elementOrList x = do

73 mbres <- Lua.peekEither topOfStack

75 mbres <- Lua.peekEither topOfStack

74 case mbres of

76 case mbres of

75 Right res -> [res] <$ Lua.pop 1

77 Right res -> [res] <$ Lua.pop 1

78+ Left _ -> do

79+ typeCheck Lua.stackTop Lua.TypeTable

76− Left _ -> Lua.toList topOfStack <* Lua.pop 1

80+ Lua.toList topOfStack `finally` Lua.pop 1

78-- | Try running a filter for the given element

82-- | Try running a filter for the given element

79tryFilter :: (Data a, FromLuaStack a, ToLuaStack a)

83tryFilter :: (Data a, FromLuaStack a, ToLuaStack a)

src/Text/Pandoc/Lua/StackInstances.hs+19−13

@@ -35,13 +35,15 @@ module Text.Pandoc.Lua.StackInstances () where

36import Control.Applicative ((<|>))

37import Control.Monad (when)

38+import Control.Monad.Catch (finally)

38import Data.Data (showConstr, toConstr)

39import Data.Data (showConstr, toConstr)

39import Data.Foldable (forM_)

40import Data.Foldable (forM_)

40import Foreign.Lua (FromLuaStack (peek), Lua, LuaInteger, LuaNumber, StackIndex,

41import Foreign.Lua (FromLuaStack (peek), Lua, LuaInteger, LuaNumber, StackIndex,

41 ToLuaStack (push), Type (..), throwLuaError, tryLua)

42 ToLuaStack (push), Type (..), throwLuaError, tryLua)

42import Text.Pandoc.Definition

43import Text.Pandoc.Definition

43import Text.Pandoc.Extensions (Extensions)

44import Text.Pandoc.Extensions (Extensions)

44−import Text.Pandoc.Lua.Util (adjustIndexBy, getTable, pushViaConstructor)

45+import Text.Pandoc.Lua.Util (adjustIndexBy, getTable, pushViaConstructor,

46+ typeCheck)

45import Text.Pandoc.Options (ReaderOptions (..), TrackChanges)

47import Text.Pandoc.Options (ReaderOptions (..), TrackChanges)

46import Text.Pandoc.Shared (Element (Blk, Sec), safeRead)

48import Text.Pandoc.Shared (Element (Blk, Sec), safeRead)

@@ -49,21 +51,27 @@ import qualified Foreign.Lua as Lua

49import qualified Data.Set as Set

51import qualified Data.Set as Set

50import qualified Text.Pandoc.Lua.Util as LuaUtil

52import qualified Text.Pandoc.Lua.Util as LuaUtil

54+defineHowTo :: String -> Lua a -> Lua a

55+defineHowTo ctx op = op `Lua.modifyLuaError` (("Could not " ++ ctx ++ ": ") ++)

56+

52instance ToLuaStack Pandoc where

57instance ToLuaStack Pandoc where

53 push (Pandoc meta blocks) =

58 push (Pandoc meta blocks) =

54 pushViaConstructor "Pandoc" blocks meta

59 pushViaConstructor "Pandoc" blocks meta

56instance FromLuaStack Pandoc where

61instance FromLuaStack Pandoc where

57− peek idx = do

62+ peek idx = defineHowTo "get Pandoc value" $ do

63+ typeCheck idx Lua.TypeTable

58 blocks <- getTable idx "blocks"

64 blocks <- getTable idx "blocks"

59− meta <- getTable idx "meta"

65+ meta <- Lua.getfield idx "meta" *> (Lua.peek Lua.stackTop `finally` Lua.pop 1)

60 return $ Pandoc meta blocks

66 return $ Pandoc meta blocks

62instance ToLuaStack Meta where

68instance ToLuaStack Meta where

63 push (Meta mmap) =

69 push (Meta mmap) =

64 pushViaConstructor "Meta" mmap

70 pushViaConstructor "Meta" mmap

65instance FromLuaStack Meta where

71instance FromLuaStack Meta where

72+ peek idx = defineHowTo "get Meta value" $ do

73+ typeCheck idx Lua.TypeTable

66− peek idx = Meta <$> peek idx

74+ Meta <$> peek idx

68instance ToLuaStack MetaValue where

76instance ToLuaStack MetaValue where

69 push = pushMetaValue

77 push = pushMetaValue

@@ -160,7 +168,7 @@ pushMetaValue = \case

160

168

161-- | Interpret the value at the given stack index as meta value.

169-- | Interpret the value at the given stack index as meta value.

162peekMetaValue :: StackIndex -> Lua MetaValue

170peekMetaValue :: StackIndex -> Lua MetaValue

163−peekMetaValue idx = do

171+peekMetaValue idx = defineHowTo "get MetaValue" $ do

164 -- Get the contents of an AST element.

172 -- Get the contents of an AST element.

165 let elementContent :: FromLuaStack a => Lua a

173 let elementContent :: FromLuaStack a => Lua a

166 elementContent = peek idx

174 elementContent = peek idx

@@ -209,7 +217,8 @@ pushBlock = \case

209

217

210-- | Return the value at the given index as block if possible.

218-- | Return the value at the given index as block if possible.

211peekBlock :: StackIndex -> Lua Block

219peekBlock :: StackIndex -> Lua Block

212−peekBlock idx = do

220+peekBlock idx = defineHowTo "get Block value" $ do

221+ typeCheck idx Lua.TypeTable

213 tag <- getTag idx

222 tag <- getTag idx

214 case tag of

223 case tag of

215 "BlockQuote" -> BlockQuote <$> elementContent

224 "BlockQuote" -> BlockQuote <$> elementContent

@@ -260,7 +269,8 @@ pushInline = \case

260

269

261-- | Return the value at the given index as inline if possible.

270-- | Return the value at the given index as inline if possible.

262peekInline :: StackIndex -> Lua Inline

271peekInline :: StackIndex -> Lua Inline

263−peekInline idx = do

272+peekInline idx = defineHowTo "get Inline value" $ do

273+ typeCheck idx Lua.TypeTable

264 tag <- getTag idx

274 tag <- getTag idx

265 case tag of

275 case tag of

266 "Cite" -> uncurry Cite <$> elementContent

276 "Cite" -> uncurry Cite <$> elementContent

@@ -296,11 +306,7 @@ getTag idx = do

296 hasMT <- Lua.getmetatable idx

306 hasMT <- Lua.getmetatable idx

297 push "tag"

307 push "tag"

298 if hasMT then Lua.rawget (-2) else Lua.rawget (idx `adjustIndexBy` 1)

308 if hasMT then Lua.rawget (-2) else Lua.rawget (idx `adjustIndexBy` 1)

299− r <- tryLua (peek (-1))

300− Lua.settop top

309+ peek Lua.stackTop `finally` Lua.settop top

301− case r of

302− Left (Lua.LuaException err) -> throwLuaError err

303− Right res -> return res

304

310

305withAttr :: (Attr -> a -> b) -> (LuaAttr, a) -> b

311withAttr :: (Attr -> a -> b) -> (LuaAttr, a) -> b

306withAttr f (attributes, x) = f (fromLuaAttr attributes) x

312withAttr f (attributes, x) = f (fromLuaAttr attributes) x

@@ -313,7 +319,7 @@ instance ToLuaStack LuaAttr where

313 pushViaConstructor "Attr" id' classes kv

319 pushViaConstructor "Attr" id' classes kv

314

320

315instance FromLuaStack LuaAttr where

321instance FromLuaStack LuaAttr where

316− peek idx = LuaAttr <$> peek idx

322+ peek idx = defineHowTo "get Attr value" (LuaAttr <$> peek idx)

317

323

318--

324--

319-- Hierarchical elements

325-- Hierarchical elements

src/Text/Pandoc/Lua/Util.hs+9

@@ -36,6 +36,7 @@ module Text.Pandoc.Lua.Util

36 , getRawInt

37 , setRawInt

38 , addRawInt

39+ , typeCheck

39 , raiseError

40 , raiseError

40 , popValue

41 , popValue

41 , PushViaCall

42 , PushViaCall

@@ -100,6 +101,14 @@ setRawInt idx key value = do

100addRawInt :: ToLuaStack a => Int -> a -> Lua ()

101addRawInt :: ToLuaStack a => Int -> a -> Lua ()

101addRawInt = setRawInt (-1)

102addRawInt = setRawInt (-1)

102

103

104+typeCheck :: StackIndex -> Lua.Type -> Lua ()

105+typeCheck idx expected = do

106+ actual <- Lua.ltype idx

107+ when (actual /= expected) $ do

108+ expName <- Lua.typename expected

109+ actName <- Lua.typename actual

110+ Lua.throwLuaError $ "expected " ++ expName ++ " but got " ++ actName ++ "."

111+

103raiseError :: ToLuaStack a => a -> Lua NumResults

112raiseError :: ToLuaStack a => a -> Lua NumResults

104raiseError e = do

113raiseError e = do

105 Lua.push e

114 Lua.push e

test/Tests/Lua.hs+10

@@ -123,6 +123,16 @@ tests = map (localOption (QuickCheckTests 20))

123 Lua.getglobal "PANDOC_API_VERSION"

124 Lua.liftIO . assertEqual "pandoc-types version is wrong" versionNums

125 =<< Lua.peek Lua.stackTop

126+

127+ , testCase "informative error messages" . runPandocLua' $ do

128+ Lua.pushboolean True

129+ err <- Lua.peekEither Lua.stackTop :: Lua.Lua (Either String Pandoc)

130+ case err of

131+ Left msg -> do

132+ let expectedMsg = "Could not get Pandoc value: "

133+ ++ "expected table but got boolean."

134+ Lua.liftIO $ assertEqual "unexpected error message" expectedMsg msg

135+ Right _ -> error "Getting a Pandoc element from a bool should fail."

126 ]

136 ]

127

137

128assertFilterConversion :: String -> FilePath -> Pandoc -> Pandoc -> Assertion

138assertFilterConversion :: String -> FilePath -> Pandoc -> Pandoc -> Assertion