Programs in embedded domain-specific languages are realized as graphs of objects of the host language rather than as static input texts. This property enables dynamic meta-programming, but also makes it harder to attach location information to diagnostic messages that arise at a later stage, after the program graph construction. Thus, EDSL-generating expressions and algorithms can be difficult to debug. Here, we present a technique for transparently capturing and replaying location information about the origin of EDSL program objects. It has been implemented in the context of the LLJava-live EDSL-to-bytecode compiler framework on the JVM. The basic idea can be generalized to other contexts, and to any managed runtime environment with reified stack traces.

Units of measure with prefixes and conversion rules are given a formal semantic model in terms of categorial group theory. Basic structures and both natural and contingent semantic operations are defined. Conversion rules are represented as a class of ternary relations with both group-like and category-like properties. A hierarchy of subclasses is explored, each satisfying stronger useful algebraic properties than the preceding, culminating in a direct efficient conversion-by-rewriting algorithm.

This paper investigates the use of staged meta-programming techniques for the transparent acceleration of embedded domain-specific languages on the Java platform. LLJava-live, the staged API of the low-level JVM language LLJava, can be used to complement an interpreted EDSL with orthogonal and extensible compilation facilities. Compiled JVM bytecode becomes available immediately as an extension of the running host program. The approach is illustrated with a didactic structured imperative programming language, Whilst.

XSLT 1.0 is a standardized functional programming language and widely used for defining transformations on XML models and documents, in many areas of industry and publishing. The problem of XSLT type checking is to verify that a given transformation, when applied to an input which conforms to a given structure definition, e.g. an XML DTD, will always produce an output which adheres to a second structure definition. This problem is known to be undecidable for the full range of XSLT and document structure definition languages. Either one or both of them must be significantly restricted, or only approximations can be calculated. The algorithm presented here takes a different approach towards type correct XSLT transformations. It does not consider the type of the input document at all. Instead it parses the fragments of the result document contained verbatim in the transformation code and verifies that these can potentially appear in the result language, as defined by a given DTD. This is a kind of abstract interpretation, which can be executed on the fly and in linear time when parsing the XSLT program. Generated error messages are located accurately to a child subsequence of a single result element node. Apparently the method eliminates a considerable share of XSLT programming errors, on the same order of magnitude as a full fledged global control-flow analysis.

Use cases are a widespread informal method for specifying the requirements of a technical system in the early development phase. Z is a formal notation which aims to support, beside others, the specification of early requirements. We develop a representation of use cases in Z and apply it to several examples. Our focus is on instrumenting the formalization for black-box test evaluation in Executable Z, a computation model and implementation for Z based on concurrent constraint resolution.