1. [Aug 2021] Delivered an ICFP keynote with record low attendance.
  2. [Mar 2021] Thank you, Ivan Reese, for hosting me on the Future of Coding podcast.

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Currently Teaching

[CMSC 11111, Winter 2022] Creative Coding
[CMSC 32001, Winter 2022] Topics in PL: User Interfaces for Programming Languages

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I enjoy developing and deploying programming language technology — type systems, synthesis algorithms, and other program analysis techniques — for applications in software engineering and human-computer interaction. Currently, the overarching theme of my research is to develop Direct Manipulation Programming Systems.

active projects

[Sketch-n-Sketch] GUIs are great, but the lack of programmability in a high-level language makes it difficult to develop complex and reusable content. Sketch-n-Sketch is a direct manipulation programming system for interactively creating documents, such as graphic designs, web pages, and spreadsheets.
[Deuce] Text editors are great, but coding involves tedious, error-prone edits that hinder productivity and creativity. Deuce is a structure-aware code editor with direct manipulation interactions for quickly performing programming and refactoring tasks.
[Hazel, led by Cyrus Omar @ Michigan] Programming environments are great, but they typically provide little help for incomplete programs — those that are syntactically ill-formed or ill-typed. This project develops semantic foundations for programming environments to continuously edit, reason about, and run programs with holes.
[Ivy] Visualization editors are great: chart choosers as in Excel are easy to use, shelf builders like Tableau faciliate rapid exploration, and textual specification languages like Vega are expressive and flexible. This project develops a framework for integrating and augmenting the benefits of multiple user interface modalities for visualization. Demo coming soon.

older projects

[Dependent JavaScript @ UCSD] Scripting languages include features that frustrate static reasoning, such as extensible objects, dynamically computed keys, loosely coupled recursion, reflection, and dynamic code loading. This project aims to develop type systems to describe idiomatic programs in scripting languages such as JavaScript, Python, and Ruby.
[Radar @ UCSD] Defining a dataflow analysis for concurrent programs is complicated by the subtleties of thread interleavings and locking protocols. Radar automatically converts a sequential dataflow analysis to a concurrent one by making use of datarace information from the Relay race detector for C programs.
[Staged Information Flow @ UCSD] The prevalence of dynamically loaded code makes program analysis for JavaScript difficult. We present a staged approach to tracking information flow that splits the analysis burden between compile-time and run-time.
[Fine @ Microsoft Research] Modern SMT solvers allow refinement type systems to track security and other complex properties, but they become a large part of the compiler's trusted computing base (TCB). Fine incorporates a type-preserving translation to eliminate the solver from the TCB. Fine is a precursor to MSR's F* language.


Brian Hempel Ph.D. student
Andrew McNutt Ph.D. student
Anton Outkine College student

former postdoctoral advisees
Mikaël Mayer CTO @ Tharzen
Cyrus Omar Assistant Professor @ University of Michigan

former graduate student advisees
Nick Collins Delta Dictionaries (MS 2021)

former undergraduate thesis advisees
Grace Lu Deuce: Direct Manipulation Source Program Editor (BS 2017)
Justin Lubin Forging Smyth: Program Sketching with Live Bidirectional Eval. (BS 2020)
Izaak Meckler Mote: Goal-Driven Development and Synthesis for Haskell (BS 2015)
Bowen Wang Predicting Haskell Type Signatures from Names (BS/MS 2018)

Professional Activities

2022: PLDI Sponsorship
2021: POPL PC, <Programming> PC, Bx PC, PLDI Sponsorship, PLDI PC, PLATEAU PC
2020: Bx PC, SYNT Co-chair, FPE PC, SPLASH Local Chair, HATRA PC, LIVE PC
2019: <Programming> PC, Bx PC, PLDI AEC Co-chair, LIVE PC, Onward! PC
2018: PX PC, PLDI AEC Co-chair, ICFP SRC Chair, LIVE Co-organizer, PLATEAU PC
2016: POPL SRC, PLDI ERC, ECOOP PC, TFP PC, Midwest PL Summit Co-organizer
2013: FOOL PC

Journal of Functional Programming, Editorial Board, 2020–
LIVE Programming Workshop, Steering Committee, 2019–
Elm Software Foundation, Board of Directors, 2016–