I am a Computer Science Ph.D. student at Northeastern University. I am a member of the Programming Research Laboratory, advised by Professor Jan Vitek. I received a Bachelors degree in Electronics and Communication Engineering from Netaji Subhas Institute of Technology.
Previously, I interned at Oracle Labs, Austria, and worked at National Center for Biological Sciences, and Yahoo!.
Research
Broadly, my research involves two direction. First, I am interested in applying programming language techniques to improve data science tools. Second, I am interested in developing mechanisms for data-driven evolution of mainstream programming languages. To explore these directions, I employ empirical evaluations, dynamic, and static analyses.
I am working primarily on the migration of R from lazy-by-default to lazy-on-demand semantics. The interaction of R's laziness with missing arguments, side-effects, metaprogramming and reflective operations introduces challenges for users, developers, and language implementors. I am trying to develop tools and algorithms to switch R's semantics with minimal impact to legacy code. To test the correctness and robustness of my approach, I am leveraging millions of lines of code available from R's official package repositories, CRAN and Bioconductor.
I am also involved in other projects related to R. For example, I am helping retrofit a type system to R motivated by empirical insights from existing R code.
Publications
OOPSLA'20- Designing Types for R, Empirically
Alexi Turcotte , Aviral Goel , Filip Křikava , Jan Vitek⸢doi:10.1145/3428249⸥ ⸢paper⸥ ⸢software⸥ ⸢talk⸥
OOPSLA'19- On the Design, Implementation, and Use of Laziness in R
Aviral Goel , Jan Vitek⸢doi:10.1145/3360579⸥ ⸢paper⸥ ⸢software⸥ ⸢talk⸥
POPL'18- Correctness of Speculative Optimizations with Dynamic Deoptimization
Olivier Flückiger , Gabriel Scherer , Ming-ho Yee , Aviral Goel , Amal Ahmed , Jan Vitek
Softwares
Frameworks
R-dyntrace- A modified R VM that provides an event framework for program execution. This forms the base of all our dynamic analyses and empirical evaluations of R. It supports over forty events related to function calls, side-effects, garbage collection, attributes, promises, environments, eval, metaprogramming, and dynamic dispatch.
instrumentr- An R package that
complements R-dyntrace by modeling all R objects and the R session for tracing
and empirical evaluations.
instrumentris a culmination of years of experience writing tracers and provides a rich API to facilitate many complex analyses used in our research papers. It accumulates a lot of metadata about R objects and provides wrapper APIs to extract fine-grained information used in dynamic analyses for object tainting and event tracking.
experimentr- An R package for
large-scale program analysis experiments related to R. First, it provides
utility functions for ranking R packages based on dependencies, extracting
runnable programs, counting lines of code, and other routine tasks. Second, it
exposes a DSL to express complex analysis pipelines as a graph of
stepabstractions with a facility to invoke the steps from command-line or a web-app based interface.
dockr- A Docker image providing a comprehensive environment for R and C/C++ development, large-scale program analysis experiments, and setting up corpus of R programs. It provides standard development tools such as emacs, gdb, valgrind, and, perf, includes all the dependencies needed to build our in-house dynamic and static analysis softwares, and contains enough native dependencies to install most of the CRAN and Bioconductor repositories ( ~20,000 R packages with ~450,000 programs).
Applications
envtracer- A dynamic analyzer for tracking first-class environments and reflective frame access in R. We are using this to understand how R developers take advantage of the first-class nature of environments and function scopes.
strictr- An R package that alters R semantics by eagerly evaluating function arguments based on strictness specifications. We are using this to study the impact of switching R's semantics from lazy-by-default to lazy-on-demand.
lazr- A dynamic analyzer for profiling laziness in R applications and
synthesizing strictness signatures. We are using this in conjunction with
strictrto propose a semi-automated laziness removal technique.
evil- A dynamic analyzer for
analyzing the use of
evalfamily of functions in R. We are using this to better understand how dynamic evaluation is employed by R package authors and how their usage patterns are different from those of Javascript developers.
contractr- An R package that inserts function argument and return type contracts and monitors failures. We used this to evaluate the design of type signatures for R for 8.7K R packages with 98M assertions.
tastr- A C++ library implementing a
grammar of type signatures for R. It provides APIs to parse type signatures
from input streams into C++ objects. This was used by
contractrto generate type contracts for 22K R functions from 412 packages.
promisedyntracer- A dynamic analysis tool to analyze use of laziness in R, specifically, evaluation of promises, side-effects, metaprogramming, and argument evaluation orders. It was used to study laziness in 230K R programs from 16,707 R packages. The tool generated 5.2 TB of execution traces from 271B promises (thunks).