Computer science, like other mathematical fields, cannot live without a tight relationship
with reality. However, such a relationship is, frankly, not very common.
This is probably why people so enthusiastically welcome a true meeting of theory
and practice. In that sense, the coming together of XML and tree automata theory
was a beautiful marriage. Thus I have written this book in the earnest hope that the
news of this marriage will be spread and celebrated all over the world!
The book is a summary of my ten years’ work. It could not have been realized
without my collaborators, Peter Buneman, Giuseppe Castagna, Alain Frisch,
Vladimir Gapeyev, Kazuhiro Inaba, Shinya Kawanaka, Hiromasa Kido, Michael
Y. Levin, Sebastian Maneth, Makoto Murata, Benjamin C. Pierce, Tadahiro Suda,
J´erˆomeVouillon, TakeshiYashiro, and PhilipWadler. In particular, I thank Kazuhiro
Inaba and Sebastian Maneth, who made uncountable comments on the draft and
thus contributed to a huge improvement of the book. Lastly, I thank my dear
wife, Ayako, who gave me the warmest and unceasing encouragement to finish the
book.
This is the first book that provides a solid theoretical account of the foundation of the popular data format XML. Part I establishes basic concepts, starting with schemas, tree automata and pattern matching, and concluding with static typechecking for XML as a highlight of the book. In Part II, the author turns his attention to more advanced topics, including efficient 'on-the-fly' tree automata algorithms, path- and logic-based queries, tree transformation, and exact typechecking. The author provides many examples of code fragments to illustrate features, and exercises to enhance understanding. Thus the book will be ideal for students and researchers whether just beginning, or experienced in XML research.