Grammar metrics have been introduced to measure the quality and the complexity of the formal grammars. The aim of this paper is to explore the meaning of these notions and to experiment, on several grammars of domain specific languages and of general-purpose languages, existing grammar metrics together with the new metrics that are based on grammar LR… (More)
The trace subshift of a cellular automaton is the subshift of all possible columns that may appear in a space-time diagram. We prove the undecidability of a rather large class of problems over trace subshifts of cellular automata.
This paper presents Tatoo, a new parser generator. This tool, written in Java 1.5, produces lexer and bottom-up parsers. Its design has been driven by three main concerns: the ability to use the parser with the non-blocking IO API; the possibility to simply deal with several language versions; a clean separation between the lexer definition, the parser… (More)
The trace subshift of a cellular automaton is the subshift of all possible columns that may appear in a space-time diagram. In this paper we study conditions for a sofic subshift to be the trace of a cellular automaton.
We introduce a new model for simulating natural phenomena. We address several issues: topology, basic set properties like injectivity and surjectivity, reversibility, and decidability questions about a special kind of conservation law called grain conservation and ultimate periodicity.
This paper presents an extension of the Tatoo compiler compiler that supports separate compilation and dynamic linking of formal grammars. It allows the developer to define reusable libraries of grammars such as those of arithmetic expressions or of classical control operators. The aim of this feature is to simplify the development of domain specific… (More)
We prove several results about the relations between injectivity and surjectivity for sand automata. Moreover, we begin the exploration of the dynamical behavior of sand automata proving that the property of ultimate periodicity is undecidable. We believe that the proof technique used for this last result might turn out to be useful for many other results… (More)