Ad hoc data formats, i.e. semistructured non-standard dataformats, are pervasive in many domains that need software tools—bioinformatics,demographic surveys, geophysics and network software are justa few. Building tools becomes easier if parsing and other standard inputoutputprocessing can be automated. Modern approaches for dealingwith ad hoc data formats consist of domain specific languages based ontype systems. Compilers for these languages generate data structures andparsing functions in a target programming language in which tools andapplications are then written. We present a monadic library in Haskellthat implements a data description language. Using our library, Haskellprogrammers have access to data description primitives that can be usedfor parsing and that can be integrated with other libraries and applicationprograms without the need of yet another compiler.

Network software is typically organized according toa layered architecture that is well understood. However, writingcorrect and efficient code that conforms with the architecture stillremains a problem. To overcome this problem we propose to usea domain specific language based approach. The architecturalconstraints are captured in a domain specific notation that can beused as a source for automatic program generation. Conformancewith the architecture is thus assured by construction. Knowledgefrom the domain allows us to generate efficient code. In addition,this approach enforces reuse of both code and designs, one ofthe major concerns in software architecture. In this paper, weillustrate our approach with PADDLE, a tool that generates packetprocessing code from packet descriptions. To describe packets weuse a domain specific language of dependent types that includespacket overlays. From the description we generate C librariesfor packet processing that are easy to integrate with other partsof the code. We include an evaluation of our tool.

Protocol stack specifications are well-structured documents that follow a number of conventions and notations that have proven very useful for the design and dissemination of communication protocols. Protocol stack implementations on the other hand, are done in low-level languages, using error-prone programming techniques resulting in programs that are difficult to relate to the specifications, difficult to maintain, modify, extend and reuse. To overcome these problems we propose a domain-specific language that provides abstractions close to the notations used in protocol specifications. From descriptions in our language we generate C programs that can be integrated with other systems software. The language provides constructs to describe packet formats, including physical layout, constraints and dependencies. It also provides constructs for state machines and for layering protocols into stacks. Experiments show that the C programs we generate are comparable in performance and binary size to hand-crafted C programs.

Network protocols today play a major role in embedded software for industrial automation, with constant efforts to adapt existing device software to new emerging standards. In earlier work, we have proposed a compilation-based approach using a domain-specific language, Protege, which automatically generates protocol stack implementations in C from modular high-level descriptions. In this paper, we provide a case study of the Protege language in an industrial setting. We have implemented the Modbus protocol over TCP/IP and over serial line, and tested it using an industrial gateway. Our implementation demonstrates Protege's advantages for software productivity, easy maintenance and code reuse, and it achieves many desirable properties of industrial embedded network software.