Question

我想解决我目前维护的rdf4h库中的错误。它支持将XML / RDF文档解析为XmlParser模块中的RDF图，但不能成功解析包含XML规范头的XML / RDF文档，例如。

<?xml version="1.0" encoding="ISO-8859-1"?>

解析器使用HXT箭头界面，即Text.XML.HXT.Core module。我已经将问题归结为函数testSuccess和testFailure中的两次解析尝试。两者都使用runSLA。 hxt的作者告诉我，问题在于xread的使用，我首先要在xread之前从字符串中提取XML文档。（不幸的是，他没有对我提出的GitHub issue做出回应。）

下面有两个字符串，两个字符串都包含相同的XML文档。 xmlDoc1字符串包含一个规范标题，该标题会抬起xread中的testFailure箭头。

module HXTProblem where

import Text.XML.HXT.Core

data GParseState = GParseState { stateGenId :: Int } deriving(Show)

-- this document has an XML specification included
xmlDoc1 :: String
xmlDoc1 = "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?>" ++
          "<shiporder orderid=\"889923\" " ++
          "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" " ++
          "xsi:noNamespaceSchemaLocation=\"shiporder.xsd\">" ++
          "<orderperson>John Smith</orderperson>" ++
             "<shipto>" ++
               "<name>Ola Nordmann</name>" ++
             "</shipto>" ++
          "</shiporder>"

-- this document does not include the XML specification
xmlDoc2 :: String
xmlDoc2 = "<shiporder orderid=\"889923\" " ++
          "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" " ++
          "xsi:noNamespaceSchemaLocation=\"shiporder.xsd\">" ++
          "<orderperson>John Smith</orderperson>" ++
             "<shipto>" ++
               "<name>Ola Nordmann</name>" ++
             "</shipto>" ++
          "</shiporder>"

initState :: GParseState
initState = GParseState { stateGenId = 0 }

-- | Works
testSuccess :: (GParseState,[XmlTree])
testSuccess = runSLA xread initState xmlDoc2

{- output of runnnig testSuccess
(GParseState {stateGenId = 0},[NTree (XTag "shiporder" [NTree (XAttr "orderid") [NTree (XText "889923") []],NTree (XAttr "xmlns:xsi") [NTree (XText "http://www.w3.org/2001/XMLSchema-instance") []],NTree (XAttr "xsi:noNamespaceSchemaLocation") [NTree (XText "shiporder.xsd") []]]) [NTree (XTag "orderperson" []) [NTree (XText "John Smith") []],NTree (XTag "shipto" []) [NTree (XTag "name" []) [NTree (XText "Ola Nordmann") []]]]]
-}

-- | Does not work
testFailure :: (GParseState,[XmlTree])
testFailure = runSLA xread initState xmlDoc1

{- ERROR running testFailure
(GParseState {stateGenId = 0},[NTree (XError 2 "\"string: \"<?xml version=\\\"1.0\\\" encoding=\\\"ISO-8859-1...\"\" (line 1, column 6):\nunexpected xml\nexpecting legal XML name character\n") []])
-}

我应该补充一点，我正在寻找使用runSLA的解决方案，该解决方案在解析XMLTree或xmlDoc1时会生成相同的xmlDoc2。

Answer 1

华友世纪，这已经解决了。 HXT库的作者已经解决GitHub issue在this commit中添加了新的解析器xreadDoc。我已经使用this commit中的这个新解析器修复了rdf4h库版本1.2.2及更高版本，因此现在可以使用XmlParser解析XML / RDF文档（带有规范和编码标题）。 / p>

请注意testFailure中的新箭头组成，为(xreadDoc >>> isElem)。

module HXTProblem where

import Text.XML.HXT.Core

data GParseState = GParseState { stateGenId :: Int } deriving(Show)

-- this document has an XML specification included
xmlDoc1 :: String
xmlDoc1 = "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?>" ++
          "<shiporder orderid=\"889923\" " ++
          "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" " ++
          "xsi:noNamespaceSchemaLocation=\"shiporder.xsd\">" ++
          "<orderperson>John Smith</orderperson>" ++
             "<shipto>" ++
               "<name>Ola Nordmann</name>" ++
             "</shipto>" ++
          "</shiporder>"

-- this document does not include the XML specification
xmlDoc2 :: String
xmlDoc2 = "<shiporder orderid=\"889923\" " ++
          "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" " ++
          "xsi:noNamespaceSchemaLocation=\"shiporder.xsd\">" ++
          "<orderperson>John Smith</orderperson>" ++
             "<shipto>" ++
               "<name>Ola Nordmann</name>" ++
             "</shipto>" ++
          "</shiporder>"

initState :: GParseState
initState = GParseState { stateGenId = 0 }

-- | Works
testSuccess :: (GParseState,[XmlTree])
testSuccess = runSLA xread initState xmlDoc2

-- | Does also now work!
testFailure :: (GParseState,[XmlTree])
testFailure = runSLA (xreadDoc >>> isElem) initState xmlDoc1

testEquality :: Bool
testEquality =
    let (_,x) = testSuccess
        (_,y) = testFailure
    in x == y

将HXT与包含规范标头的XML文档一起使用

1 个答案: