The R programming language is very popular for developing statistical software and data analysis, thanks to rich libraries, concise and expressive syntax, and support for interactive programming. Yet, the semantics of R is fairly complex, contains many subtle corner cases, and is not formally specified. This makes it difficult to reason about R programs. In this work, we develop a big-step operational semantics for R in the form of an interpreter written in the Coq proof assistant. We ensure the trustworthiness of the formalization by introducing a monadic encoding that allows the Coq interpreter, CoqR, to be in direct visual correspondence with the reference R interpreter, GNU R. Additionally, we provide a testing framework that supports systematic comparison of CoqR and GNU R. In its current state, CoqR covers the nucleus of the R language as well as numerous additional features, making it pass a significant number of realistic test cases from the GNU R and FastR projects. To exercise the formal specification, we prove in Coq the preservation of memory invariants in selected parts of the interpreter. This work is an important first step towards a robust environment for formal verification of R programs.
Tue 6 NovDisplayed time zone: Guadalajara, Mexico City, Monterrey change
10:30 - 12:00 | |||
10:30 30mTalk | The Behavior of Gradual Types: A User Study DLS 2018 Preston Tunnell Wilson Brown University, USA, Ben Greenman Northeastern University, USA, Justin Pombrio Brown University, USA, Shriram Krishnamurthi Brown University, USA | ||
11:00 30mTalk | A Trustworthy Mechanized Formalization of R DLS 2018 Martin Bodin Imperial College London, Tomás Diaz University of Chile, Chile, Éric Tanter University of Chile & Inria Paris |