DIVERSE EXECUTABLE SEMANTICS DEFINITIONS IN NUS L AND AN IMPLEMENTATION OF FUNCTIONAL TYPE S Xinjie Jian g Dept . of Mathematic s Nanjing Normal Universit y Nanjing, CHIN A Yongsen Xu Dept . of Computer Scienc e Nanjing Universit y Nanjing, CHIN A ABSTRACT Several different semantics definitions of a sample language, SAL, ar e given, all in NUSL . Their differences and similarities, and mor e generally, different approaches to the definition of programmin g languages are discussed . The implementation of functional types i s explored . 1 . INTRODUCTION There are several approaches to the definition of programmin g languages, among them are the operational and denotational semantics . An operational semantics specifies a language by defining an interprete r for the abstract syntax of the language, thus an operational definitio n is executable, at least, theoretically . The denotational semantics of a language defines what each grammatical unit denotes in some well-define d mathematical model . The meaning of a particular syntactic construct i s defined in terms of the meanings of its immediate subcomponents [Sto y 77] . The algebraic approach to abstract data types [Goguen 78] is als o employed to define
/lp/association-for-computing-machinery/diverse-executable-semantics-definitions-in-nusl-and-an-implementation-UgS55rDmyH