Expat XML parser
https://libexpat.github.io/
https://qiita.com/zinbe/items/0516e58cea479e95f6bf
https://hackage.haskell.org/package/hxt-expat-9.1.1/docs/Text-XML-HXT-Expat.html
HXT
向けのmoduleがある
stream orientedな
XML parser
https://github.com/libexpat/libexpat