Agustín Cernuda del Río

LPS: A Language Prototyping System Using Modular Monadic Semantics

Abstract This paper describes LPS, a Language Prototyping System that facilitates the modular development of interpreters from semantic building blocks. The system is based on the integration of ideas from Modular Monadic Semantics and Generic Programming. To define a new programming language, the abstract syntax is described as the fixpoint of non-recursive pattern functors. For each functor an algebra is defined whose carrier is the computational monad obtained from the application of several monad transformers to a base monad. The interpreter is automatically generated by a catamorphism or, in some special cases, a monadic catamorphism. The system has been implemented as a domain-specific language embedded in Haskell and we have also implemented an interactive framework for language testing.

A monadic program slicer

Program slicing is an important decomposition technique. It has been widely used in many software activities, such as software analyzing, understanding, debugging, testing, and maintenance. The current slicing methods and tools, however, are monolithic, and mainly based on program or system dependence graph. This paper presents a novel formal tool for program slicing. It abstracts the computation of program slicing as a language-independent slice monad transformer, which can be applied to the semantic descriptions of the program in a modular way, forming the corresponding slicing algorithms. Such algorithms allow program slices to be computed directly on abstract syntax, with no need to explicitly construct intermediate structures such as dependence graphs or to record an execution history. It has reusability and language-flexibility properties in comparison with the current program slicing methods/tools.