Many tools designed to help programmers view and manipulate source code exploit the formal structure of the programming language. Language-based tools use information derived via linguistic analysis to offer services that are impractical for purely text-based tools. In order to be effective, however, language-based tools must be designed to account properly for the documentary structure of source code: a structure that is largely orthogonal to the linguistic but no less important. Documentary structure includes, in addition to the language text, all extra-lingual information added by programmers for the sole purpose of aiding the human reader: comments, white space, and choice of names. Largely ignored in the research literature, documentary structure occupies a central role in the practice of programming. An examination of the documentary structure of programs leads to a better understanding of requirements for tool architectures.

Abstract. We are concerned with the design of programming languages that support the paradigm of component-oriented programming. Languages based on the accepted idea of combining modular and objectoriented concepts fail to provide adequate support. We argue that messages should be separated from methods to address this shortcoming. We introduce the concept of stand-alone messages, give examples for its utility, and compare it to related approaches and language constructs. Besides leading to interesting insights on the interaction of modular and object-oriented concepts, we believe that stand-alone messages also provide a useful basis for further research on component-oriented programming languages. 1

Through dynamic linking, Java supports a novel paradigm for code deployment, which ensures fast program start-up and linking with the most recent version of code. Thus Java dynamic linking, gives support for software evolution, by supporting a piece of code A which uses a piece of code B, to link at run-time with a version of code B which was created after A was created. Dynamic linking involves loading, verification, resolution and preparation of code. Programmers are normally not aware of the dynamic linking process. Nevertheless, in some situations, dynamic linking does manifest itself, and affects program execution and the integrity of the virtual machine. Therefore, there is a need for a description of dynamic linking at the level of the Java source language. We provide such a description, and demonstrate the process in terms of a sequence of source language examples, in which the effects if dynamic linking are explicit. 1.

Extension languages are an important part of modern applications development. Java as a platform does not provide a standard extension language. Scheme is one possible choice as an extension language for Java. There are a variety of techniques for implementing Scheme in Java varying from interpreting s-expressions to compiling into Java byte-codes. The historical evolution of one implementation is discussed over the course of several years. The design of the Java-to-Scheme and Scheme-to-Java interfaces is reviewed. The advantages and disadvantages of Java and Scheme are compared.

It is easy to imagine machines that can communicate in natural language. Constructing such machines is more difficult. The aim of this thesis is to demonstrate and concrete syntax make it easier to develop natural language applications. We describe how the type-theorectical grammar formalism Grammatical Framework (GF) can be used as a high-level language for natural language applications. By taking advantage of techniques from the field of programming language implementation, we can use GF grammars to perform portable and efficient parsing and linearization, generate speech recognition language models, implement multimodal fusion and fission, generate support code for abstract syntax transformations, generate dialogue managers, and implement speech translators and web-based syntax-aware editors. By generating application components from a declarative grammar, we can reduce duplicated work, ensure consistency, make it easier to build multilingual systems, improve linguistic quality, enable re-use across system domains, and