Abstract not found

We survey work on statically type checking XML transformations, covering a wide range of notations and ambitions. The concept of type may vary from idealizations of DTD to full-blown XML Schema or even more expressive formalisms. The notion of transformation may vary from clean and simple transductions to domain-specific languages or integration of XML in general-purpose programming languages. Type annotations can be either explicit or implicit, and type checking ranges from exact decidability to pragmatic approximations. We characterize

Xtatic is a lightweight extension of C ♯ with native support for statically typed XML processing. It features XML trees as built-in values, a refined type system based on regular types in the style of XDuce, and “tree grep”-style regular patterns for traversing and manipulating XML. Previous papers on Xtatic have reported results on a number of specific technical issues: basic theoretical properties of an idealized core language, novel compilation algorithms for regular pattern matching, and efficient runtime support for XML processing in the style encouraged by Xtatic. The aim of the present paper is to discuss Xtatic—less formally and more holistically—from the perspective of language design. We survey the most significant issues we faced in the design process and evaluate the choices we have made in addressing them. <person> <name>Haruo Hosoya</name>

Abstract. Xtatic is a lightweight extension of C ♯ offering native support for statically typed XML processing. XML trees are built-in values in Xtatic, and static analysis of the trees manipulated by programs is part of the ordinary job of the typechecker. “Tree grep ” pattern matching is used to investigate and transform XML trees. Xtatic’s surface syntax and type system are tightly integrated with those of C ♯. Beneath the hood, however, an implementation of Xtatic must address a number of issues common to any language supporting a declarative style of XML processing (e.g., XQuery, XSLT, XDuce, CDuce, Xact, Xen, etc.). In particular, it must provide representations for XML tags, trees, and textual data that use memory efficiently, support efficient pattern matching, allow maximal sharing of common substructures, and permit separate compilation. We analyze these representation choices in detail and describe the solutions used by the Xtatic compiler. 1

XTATIC is a lightweight extension of C ♯ with native support for statically typed XML processing. It features XML trees as built-in values, a refined type system based on regular types à la XDUCE, and regular patterns for investigating and manipulating XML. We describe our experiences using XTATIC in a real-world application: a program for transforming XMLSPEC, a format used for authoring W3C technical reports, into HTML. Our implementation closely follows an existing one written in XSLT, facilitating comparison of the two languages and analysis of the costs and benefits—both significant—of rich static typing for XML-intensive code.

Web services in the context of an Enterprise Service Bus provide an architectural approach to decomposing IT solutions into reusable pieces readily responsive to changing business demands. Developing a web service involves working with two different primary decompositions: the object-oriented design and the XML document structure. XML message transformations, such as encryption and adaptation, often manifest as crosscutting concerns. Some existing middleware standards address such document-oriented concerns by allowing custom Handlers to intercept and transform XML messages at various times during a service invocation. However, handlers do not support the sound software-engineering principle of “programming to an interface”. Their coarse-grained interface makes it difficult to map the design of concerns to the implementation and prevents useful static checking by a language compiler (e.g. checking whether two handlers may perform conflicting actions). To address this and similar design challenges, we have developed a new programming model, called Doxpects, which simplifies the development and maintenance of Handlers. The main benefit of Doxpects is the ability to perform XML document transformation tasks (insertion, deletion, and replacement) in a familiar