TRX: A Formally Verified Parser Interpreter

A Formally Verified Interpreter for a Shell-Like Programming Language

The shell language is widely used for various system administration tasks on UNIX machines, as for instance as part of the installation process of software packages in FOSS distributions. Our mid-term goal is to analyze these scripts as part of an ongoing effort to use formal methods for the quality assurance of software distributions, to prove their correctness, or to pinpoint bugs. However, t...

Verified LISP Implementations on ARM, x86 and PowerPC

This paper reports on a case study, which we believe is the first to produce a formally verified end-to-end implementation of a functional programming language running on commercial processors. Interpreters for the core of McCarthy’s LISP 1.5 were implemented in ARM, x86 and PowerPC machine code, and proved to correctly parse, evaluate and print LISP s-expressions. The proof of evaluation requi...

Semantics Interpreter Document Parser Named Entity Tagger Part of Speech Tagger WordNet Matcher

Validating LR(1) Parsers

An LR(1) parser is a finite-state automaton, equipped with a stack, which uses a combination of its current state and one lookahead symbol in order to determine which action to perform next. We present a validator which, when applied to a context-free grammar G and an automaton A, checks that A and G agree. Validating the parser provides the correctness guarantees required by verified compilers...

15–212: Fundamental Structures of Computer Science II Some Notes on Interpreters

Specifications are an indispensible part of software development. They explain what must be implemented without necessarily saying how. Depending of the nature of the problem domain, specifications may range from incomplete, natural language descriptions to mathematically precise formulations of the functionality to be implemented. Much of the task of software engineering is to decompose a larg...