Question

我的目标是从这个XML文件中提取两个列表的列表：

<famous_people>
  <famous_person>
    <first_name>Wolfgang</first_name>
    <last_name>Goethe</last_name>
    <year_of_birth>1749</year_of_birth>
    <country_of_origin>Germany</country_of_origin>
  </famous_person>
  <famous_person>
    <first_name>Miguel</first_name>
    <last_name>Cervantes</last_name>
    <widely_known_for>Don Quixote</widely_known_for>
  </famous_person>
</famous_people>

我有兴趣提取的清单是：

[[("first_name","Wolfgang"),("last_name","Goethe"),("year_of_birth","1749"),("country_of_origin","Germany")],[("first_name","Miguel"),("last_name","Cervantes"),("widely_known_for","Don Quixote")]]

我只是设法达到了我感兴趣的所有元组都位于一个大的平面列表中的点，正如GHCi输出所证明的那样：

Prelude> import Text.XML.HXT.Core
Prelude Text.XML.HXT.Core> import Text.HandsomeSoup
Prelude Text.XML.HXT.Core Text.HandsomeSoup> 
Prelude Text.XML.HXT.Core Text.HandsomeSoup> html <- readFile "test.html"
Prelude Text.XML.HXT.Core Text.HandsomeSoup> 
Prelude Text.XML.HXT.Core Text.HandsomeSoup> let doc = readString [] html
Prelude Text.XML.HXT.Core Text.HandsomeSoup> 
Prelude Text.XML.HXT.Core Text.HandsomeSoup> runX $ doc >>> getChildren >>> getChildren >>> getChildren >>> multi (getName &&& deep getText)
[("first_name","Wolfgang"),("last_name","Goethe"),("year_of_birth","1749"),("country_of_origin","Germany"),("first_name","Miguel"),("last_name","Cervantes"),("widely_known_for","Don Quixote")]

如何获得所需的两个列表列表？

Answer 1

我使用listA函数在列表中收集结果。这是我的代码：

module Famous where
import Text.XML.HXT.Core (isElem, hasName, getChildren, getText, listA, runX, readDocument, getName)
import Control.Arrow.ArrowTree (deep)
import Control.Arrow ((>>>), (&&&))
import Text.XML.HXT.Arrow.XmlArrow (ArrowXml)
import Text.XML.HXT.DOM.TypeDefs (XmlTree)

atTag :: ArrowXml a => String -> a XmlTree XmlTree
atTag tag = deep (isElem >>> hasName tag)

parseFamous :: ArrowXml a => a XmlTree [(String, String)]
parseFamous = atTag "famous_person" >>> listA (getChildren >>>
                                               (getName &&& (getChildren >>> getText)))



main :: IO ()
main = do
  let path = "famous.xml"
  result <- runX (readDocument [] path >>> parseFamous)
  print result

使用HXT解析XML

1 个答案: