@phdthesis{Ostermayer2017,
  author    = {Ostermayer, Ludwig},
  title     = {Integration of Prolog and Java with the Connector Architecture CAPJa},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150713},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Modern software is often realized as a modular combination of subsystems for, e. g., knowledge management, visualization, verification, or the interaction with users. As a result, software libraries from possibly different programming languages have to work together. Even more complex the case is if different programming paradigms have to be combined. This type of diversification of programming languages and paradigms in just one software application can only be mastered by mechanisms for a seamless integration of the involved programming languages. However, the integration of the common logic programming language Prolog and the popular object-oriented programming language Java is complicated by various interoperability problems which stem on the one hand from the paradigmatic gap between the programming languages, and on the other hand, from the diversity of the available Prolog systems. The subject of the thesis is the investigation of novel mechanisms for the integration of logic programming in Prolog and object-oriented programming in Java. We are particularly interested in an object-oriented, uniform approach which is not specific to just one Prolog system. Therefore, we have first identified several important criteria for the seamless integration of Prolog and Java from the object-oriented perspective. The main contribution of the thesis is a novel integration framework called the Connector Architecture for Prolog and Java (CAPJa). The framework is completely implemented in Java and imposes no modifications to the Java Virtual Machine or Prolog. CAPJa provides a semi-automated mechanism for the integration of Prolog predicates into Java. For compact, readable, and object-oriented queries to Prolog, CAPJa exploits lambda expressions with conditional and relational operators in Java. The communication between Java and Prolog is based on a fully automated mapping of Java objects to Prolog terms, and vice versa. In Java, an extensible system of gateways provides connectivity with various Prolog system and, moreover, makes any connected Prolog system easily interchangeable, without major adaption in Java.},
  subject      = {Logische Programmierung},
  language  = {en}
}
@phdthesis{Nogatz2023,
  author    = {Nogatz, Falco},
  title     = {Defining and Implementing Domain-Specific Languages with Prolog},
  doi       = {10.25972/OPUS-30187},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301872},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {The landscape of today's programming languages is manifold. With the diversity of applications, the difficulty of adequately addressing and specifying the used programs increases. This often leads to newly designed and implemented domain-specific languages. They enable domain experts to express knowledge in their preferred format, resulting in more readable and concise programs. Due to its flexible and declarative syntax without reserved keywords, the logic programming language Prolog is particularly suitable for defining and embedding domain-specific languages. This thesis addresses the questions and challenges that arise when integrating domain-specific languages into Prolog. We compare the two approaches to define them either externally or internally, and provide assisting tools for each. The grammar of a formal language is usually defined in the extended Backus-Naur form. In this work, we handle this formalism as a domain-specific language in Prolog, and define term expansions that allow to translate it into equivalent definite clause grammars. We present the package library(dcg4pt) for SWI-Prolog, which enriches them by an additional argument to automatically process the term's corresponding parse tree. To simplify the work with definite clause grammars, we visualise their application by a web-based tracer. The external integration of domain-specific languages requires the programmer to keep the grammar, parser, and interpreter in sync. In many cases, domain-specific languages can instead be directly embedded into Prolog by providing appropriate operator definitions. In addition, we propose syntactic extensions for Prolog to expand its expressiveness, for instance to state logic formulas with their connectives verbatim. This allows to use all tools that were originally written for Prolog, for instance code linters and editors with syntax highlighting. We present the package library(plammar), a standard-compliant parser for Prolog source code, written in Prolog. It is able to automatically infer from example sentences the required operator definitions with their classes and precedences as well as the required Prolog language extensions. As a result, we can automatically answer the question: Is it possible to model these example sentences as valid Prolog clauses, and how? We discuss and apply the two approaches to internal and external integrations for several domain-specific languages, namely the extended Backus-Naur form, GraphQL, XPath, and a controlled natural language to represent expert rules in if-then form. The created toolchain with library(dcg4pt) and library(plammar) yields new application opportunities for static Prolog source code analysis, which we also present.},
  subject      = {PROLOG <Programmiersprache>},
  language  = {en}
}