Extensible Markup Language (XML) is one of the core technologies currently used both for the Web and in data/document-related representations. In most cases, developers use the standard document object model (DOM) approach in their implementations to parse, create, and modify XML documents. This means that anyone who understands core DOM can write XML implementations.
Hosoya’s theoretical book goes far beyond the simple and easy-to-understand DOM approach. He actually wants to create the theoretical foundations for XML. This is a nontrivial undertaking since, in contrast to reading XML books, it requires a firm theoretical background in computer science.
The book consists of two main parts: “Basic Topics” and “Advanced Topics.”
The fact that Part 1 is referred to as “basic” does not mean that it is easy to read. After a very rudimentary XML introduction--readers should actually already know XML--the author begins to explain tree automata and pattern matching, which, in later chapters, he applies to XML schemas and type checking.
The advanced chapters cover algorithms dealing with various adaptations, modifications, and improvements of the presented topics. They also touch on XPath and “caterpillar expressions,” an alternative to XPath. One chapter covers logic-based queries to retrieve nodes from XML.
Who is the target audience for this book? It is definitely not XML developers who normally use DOM as their core implementation background. The book requires too much theoretical knowledge, and a practitioner would not gain much from a firm theoretical foundation. The book is obviously interesting to theoretical computer scientists, and to developers who may implement their own XML parsers and retrieval mechanisms (it provides hints for the underlying implementations). Instructors at a university may also use the book in an advanced course on XML. It contains several exercises, with solutions.
The book requires some work and reflection if you’re not a theoretical computer scientist who works daily with these types of themes.
