Can Kanna parse and extract information from XML documents?

Yes, Kanna is a Swift library that can parse and extract information from XML documents. Kanna provides a way to use XPath and CSS selectors to navigate and search through XML and HTML documents, which is very useful for web scraping or data mining tasks.

To use Kanna for parsing XML in a Swift project, you would first need to install it by including it in your Podfile if you're using CocoaPods, or by adding it as a package dependency if you're using Swift Package Manager.

Here is a simple example of how you might use Kanna to parse and extract information from an XML document in Swift:

import Kanna

let xmlString = """
<?xml version="1.0" encoding="UTF-8"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications with XML.</description>
   </book>
   <book id="bk102">
      <author>Ralls, Kim</author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>A former architect battles corporate zombies.</description>
   </book>
   <!-- More books... -->
</catalog>
"""

do {
    // Parse the XML string
    let doc = try Kanna.XML(xml: xmlString, encoding: .utf8)

    // Iterate through each `book` element in the XML
    for book in doc.xpath("//book") {
        let author = book.xpath("author").first?.text ?? ""
        let title = book.xpath("title").first?.text ?? ""
        let genre = book.xpath("genre").first?.text ?? ""
        let price = book.xpath("price").first?.text ?? ""

        print("Book:")
        print("Author: \(author)")
        print("Title: \(title)")
        print("Genre: \(genre)")
        print("Price: \(price)")
        print("--------------------")
    }
} catch {
    print(error)
}

In this example, we create a string that contains XML data. We then parse it using Kanna's XML initializer, which takes the XML string and its encoding. After parsing, we use XPath queries to extract information about each book in the catalog. We print the author, title, genre, and price for each book.

Remember that Kanna is a Swift library and is not available for languages outside the Apple ecosystem. For similar functionality in Python, you'd typically use libraries like lxml or BeautifulSoup, and in JavaScript (Node.js), you might use cheerio or jsdom.