xml-enumerator 0.2.0 → 0.2.0.1
raw patch · 3 files changed
+45/−22 lines, 3 files
Files
- Text/XML/Enumerator/Parse.hs +25/−21
- runtests.hs +19/−0
- xml-enumerator.cabal +1/−1
Text/XML/Enumerator/Parse.hs view
@@ -4,12 +4,6 @@ -- documents into a stream of events, and a set of parser combinators for -- dealing with a stream of events. ----- The important thing to know about the combinators is that they do /not/ work--- on the fully-powered 'Event' datatype; rather, this module defines an--- 'SEvent' datatype which only deals with tags, attributes and content. For--- most uses, this is sufficient. If you need to parse doctypes, instructions--- or contents, you will not be able to use the combinators.--- -- As a simple example, if you have the following XML file: -- -- > <?xml version="1.0" encoding="utf-8"?>@@ -27,11 +21,11 @@ -- > data Person = Person { age :: Int, name :: Text } -- > deriving Show -- > --- > parsePerson = tag' "person" (requireAttr "age") $ \age -> do--- > name <- content'+-- > parsePerson = tagName "person" (requireAttr "age") $ \age -> do+-- > name <- content -- > return $ Person (read $ unpack age) name -- > --- > parsePeople = tag'' "people" $ many parsePerson+-- > parsePeople = tagNoAttr "people" $ many parsePerson -- > -- > main = parseFile_ "people.xml" (const Nothing) $ force "people required" parsePeople --@@ -368,7 +362,9 @@ data ContentType = Ignore | IsContent Text | IsError String | NotContent --- | Grabs the next piece of content if available.+-- | Grabs the next piece of content if available. This function skips over any+-- comments and instructions and concatenates all content until the next start+-- or end tag. contentMaybe :: Monad m => Iteratee Event m (Maybe Text) contentMaybe = do x <- E.peek@@ -401,6 +397,7 @@ NotContent -> return $ T.concat $ front [] -- | Grabs the next piece of content. If none if available, returns 'T.empty'.+-- This is simply a wrapper around 'contentMaybe'. content :: Monad m => Iteratee Event m Text content = do x <- contentMaybe@@ -415,6 +412,8 @@ -- This function automatically absorbs its balancing closing tag, and will -- throw an exception if not all of the attributes or child elements are -- consumed. If you want to allow extra attributes, see 'ignoreAttrs'.+--+-- This function automatically ignores comments, instructions and whitespace. tag :: Monad m => (Name -> Maybe a) -> (a -> AttrParser b)@@ -482,8 +481,8 @@ tagNoAttr :: Monad m => Name -> Iteratee Event m a -> Iteratee Event m (Maybe a) tagNoAttr name f = tagName name (return ()) $ const f --- | Get the value of the first parser which returns 'Just'. If none return--- 'Just', returns 'Nothing'.+-- | Get the value of the first parser which returns 'Just'. If no parsers+-- succeed (i.e., return 'Just'), this function returns 'Nothing'. choose :: Monad m => [Iteratee Event m (Maybe a)] -> Iteratee Event m (Maybe a)@@ -516,9 +515,8 @@ go (Right a) = return a -- | A helper function which reads a file from disk using 'enumFile', detects--- character encoding using 'detectUtf', parses the XML using 'parseBytes',--- converts to an 'SEvent' stream using 'simplify' and then handing off control--- to your supplied parser.+-- character encoding using 'detectUtf', parses the XML using 'parseBytes', and+-- then hands off control to your supplied parser. parseFile :: FilePath -> DecodeEntities -> Iteratee Event IO a@@ -527,11 +525,13 @@ run $ enumFile fn $$ joinI $ parseBytes de $$ p +-- | Parse an event stream from a lazy 'L.ByteString'. parseLBS :: L.ByteString -> DecodeEntities -> Iteratee Event IO a -> IO (Either SomeException a) parseLBS lbs de p = run $ enumSingle (L.toChunks lbs) $$ joinI $ parseBytes de $$ p +-- | Same as 'parseLBS', but throws exceptions. parseLBS_ :: L.ByteString -> DecodeEntities -> Iteratee Event IO a -> IO a parseLBS_ lbs de p = run_ $ enumSingle (L.toChunks lbs) $$ joinI@@ -639,21 +639,25 @@ ignoreSiblings' = many (choose [ignoreElem', ignoreContent]) -} --- | Iteratee to skip the siblings element. +-- | Iteratee to skip sibling elements. ignoreSiblings :: Monad m => Iteratee Event m () ignoreSiblings = E.continue (loop 0) where loop :: Monad m => Int -> Stream Event -> Iteratee Event m () loop n (Chunks []) = E.continue (loop n)- loop n chs@(Chunks (x:_)) = case x of- (EventBeginElement _ _) -> E.continue (loop (n+1))+ loop n chs@(Chunks (x:xs)) = case x of+ (EventBeginElement _ _) -> case xs of+ (EventEndElement _:_) -> E.continue (loop n)+ _ -> E.continue (loop (n+1)) (EventEndElement _) | n == 0 -> yield () chs | otherwise -> E.continue (loop (n-1)) _ -> E.continue (loop n) loop _ EOF = throwError $ XmlException "Unbalanced xml-tree. (Error in skipSiblings)" Nothing --- | Iteratee to skip the next element. +-- | Iteratee to skip the next element. Skips all events before the next+-- element as well. Returns 'Nothing' if a element end event is encountered+-- before any element begin events. ignoreElem :: Monad m => Iteratee Event m (Maybe ()) ignoreElem = E.continue (loop 0) where@@ -662,13 +666,13 @@ loop n chs@(Chunks (x:xs)) = case x of (EventBeginElement _ _) -> E.continue (loop (n+1)) (EventEndElement _)- | n == 0 -> yield Nothing chs + | n == 0 -> yield Nothing chs -- FIXME in the future, it would probably make more sense to use Bool in place of Maybe () | n == 1 -> yield (Just ()) (Chunks xs) | otherwise -> E.continue (loop (n-1)) _ -> E.continue (loop n) loop _ EOF = throwError $ XmlException "Unbalanced xml-tree. (Error in skipSiblings)" Nothing --- | Skip the siblings elements until iteratee not right. +-- | Skip the sibling elements until iteratee returns 'Just'. skipTill :: Monad m => Iteratee Event m (Maybe a) -> Iteratee Event m (Maybe a) skipTill i = go where
runtests.hs view
@@ -17,6 +17,7 @@ main = hspec $ describe "XML parsing and rendering" [ it "is idempotent to parse and render a document" documentParseRender , it "has valid parser combinators" combinators+ , it "has working ignoreSiblings function" testIgnoreSiblings ] documentParseRender =@@ -65,5 +66,23 @@ , "<!-- this should be ignored -->" , "<child2> </child2>" , "<child3>combine <all> <![CDATA[&content]]></child3>\n"+ , "</hello>"+ ]++testIgnoreSiblings = P.parseLBS_ input decodeEntities $ do+ P.force "need hello" $ P.tagNoAttr "hello" $ do+ P.ignoreSiblings+ return ()+ where+ input = L.concat+ [ "<?xml version='1.0'?>\n"+ , "<!DOCTYPE foo []>\n"+ , "<hello>"+ , "<success/>"+ , "<ignore>"+ , "<nested>"+ , "<fail/>"+ , "</nested>"+ , "</ignore>\n" , "</hello>" ]
xml-enumerator.cabal view
@@ -1,5 +1,5 @@ name: xml-enumerator-version: 0.2.0+version: 0.2.0.1 license: BSD3 license-file: LICENSE author: Michael Snoyman <michaels@suite-sol.com>