Algebraic specification : syntax, semantics, structure

Algebraic specification is the technique of using algebras to model properties of a system and using axioms to characterize such algebras. Algebraic specification comprises two aspects: the underlying logic used in the axioms and algebras, and the use of a small, general set of operators to build specifications in a structured manner. We describe these two aspects using the unifying notion of institutions. An institution is an abstraction of a logical system, describing the vocabulary, the kinds of axioms, the kinds of algebras, and the relation between them. Using institutions, one can define general structuring operators which are independent of the underlying logic. In this paper, we survey the different kind of logics, syntax, semantics, and structuring operators that have been used in algebraic specification

An Introduction to Action Semantics

Formal semantics is a topic of major importance in the study of programming languages. Its applications include documenting language design, establishing standards for implementations, reasoning about programs, and generating compilers. These notes introduce action semantics, a recently-developed framework for formal semantics. The primary aim of action semantics is to allow useful semantic descriptions of realistic programming languages

Determinist Inquiries: Debates on the Foundation of Language

oai:ijcst.journals.yorku.ca:article/16147The present article intends to discuss the important determinist traditions in linguistic thought and theorizing. It will show that (1) there is a significant language-internal approach to determinism and relativity introduced by Saussure and ignored by almost all language scholars; (2) the recent trend introduced by Chomsky within the generative enterprise known as the Minimalist Program has opened a new front which makes possible an attempt to be made with the aim to reconcile, yet not to fuse, the apparently conflicting and contradictory relativist and universalist approaches to language; (3) both the Saussurean and Chomskyan conceptions of ‘sentence,’ ‘creativity,’ and hence ‘language’ are misguided and misleading; and (4) we may suggest a minimalist version of Universal Grammar, called Unified Theory of Parameters (UTP) which on the one hand in pursuit of minimalist aims sets as its objective to dispense with ‘principles’ altogether and on the other hand allows no/bi-valuation possibilities for parameters. Such a version will accommodate a perspective from which nature—genetic/innate foundation of language is complementary to nurture—environmental forces of change and adaptation

Happy-GLL: modular, reusable and complete top-down parsers for parameterized nonterminals

Parser generators and parser combinator libraries are the most popular tools for producing parsers. Parser combinators use the host language to provide reusable components in the form of higher-order functions with parsers as parameters. Very few parser generators support this kind of reuse through abstraction and even fewer generate parsers that are as modular and reusable as the parts of the grammar for which they are produced. This paper presents a strategy for generating modular, reusable and complete top-down parsers from syntax descriptions with parameterized nonterminals, based on the FUN-GLL variant of the GLL algorithm. The strategy is discussed and demonstrated as a novel back-end for the Happy parser generator. Happy grammars can contain `parameterized nonterminals' in which parameters abstract over grammar symbols, granting an abstraction mechanism to define reusable grammar operators. However, the existing Happy back-ends do not deliver on the full potential of parameterized nonterminals as parameterized nonterminals cannot be reused across grammars. Moreover, the parser generation process may fail to terminate or may result in exponentially large parsers generated in an exponential amount of time. The GLL back-end presented in this paper implements parameterized nonterminals successfully by generating higher-order functions that resemble parser combinators, inheriting all the advantages of top-down parsing. The back-end is capable of generating parsers for the full class of context-free grammars, generates parsers in linear time and generates parsers that find all derivations of the input string. To our knowledge, the presented GLL back-end makes Happy the first parser generator that combines all these features. This paper describes the translation procedure of the GLL back-end and compares it to the LALR and GLR back-ends of Happy in several experiments.Comment: 15 page