Cyrus Omar designs intelligent user interfaces for programming languages.


Carnegie Mellon University
PhD, Computer Science
BS, Computer Science
BS, Molecular & Cellular Biology


Programming Languages
EECS 490 · W20, F20, W21


PhD Students

MS Students

  • Hannah Potter
  • Erin Deutschman


There are 20+ undergraduate reseachers in FP Lab — see the FP Lab webpage!

Recent & Upcoming Talks

Midwest PL Summit talk on Hazel at Purdue
Sep. 23, 2019
TyDe 2019 talk on livelits in Hazel at ICFP in Berlin
August 18, 2019
June 6, 2019
POPL 2019 paper talk in Lisbon
Jan 17, 2019
FP Meetup + Reason Meetup joint talk on Relit in Chicago
Nov 19, 2018
LIVE talk on Hazel at SPLASH in Boston
Nov 6, 2018
META talk on Relit at SPLASH in Boston
Nov 5, 2018
POP seminar on Hazel at CMU
Oct 31, 2018
Midwest PL Summit talk on Hazel at UW Madison
Oct 12, 2018
Strange Loop talk on Hazel in St. Louis
Sep 28, 2018
ICFP 2018 paper talk in St. Louis
Sep 24, 2018


ICFP PC · CSE DEI Committee · CSE Hosting Committee
TyDe Co-Chair · MWPLS Co-Chair · ICFP ERC · ICFP SRC · HATRA PC · LIVE PC · CSE DEI Committee
Onward! PC · ML Workshop PC · META PC · LIVE PC · ICFP AEC
GPCE Publicity Chair · GPCE PC · META PC
I lead the Future of Programming Lab (FP Lab), part of the vibrant MPLSE research community.
Recent Publications & Projects

Hazel: Live Functional Programming with Typed Holes

FP Lab is the academic home of Hazel, a new kind of live programming environment that can understand, manipulate, and run incomplete programs, i.e. programs with holes. The following publications develop the semantic foundations for Hazel.

POPL 2017
Cyrus Omar, Ian Voysey, Michael Hilton, Jonathan Aldrich and Matthew A. Hammer
POPL 2019
Cyrus Omar, Ian Voysey, Ravi Chugh and Matthew A. Hammer

These papers serve as the foundation for our ongoing research into the future of programming environments.

The National Science Foundation recently selected our research proposal for three years of funding.
There has been a great deal of excitement around Hazel, e.g. at Strange Loop and on Twitter [1, 2, 3, 4, 5, 6, 7]!

Hazel Assistant: Integrative Foundations for Intelligent Programming Assistants

We are developing an intelligent programming assistant that synthesizes code satisfying specifications provided by human programmers in the form of types, tests, and sketches, and further guided by a learned understanding of idiomatic code.

To start with, we have developed the Smyth synthesizer, which adds support for sketching to Myth, a type-and-example directed synthesizer, by combining the live programming mechanisms from Hazel with a novel form of unevaluation, which propagates constraints to where they are relevant. This solves a long-standing problem: we no longer need trace-complete examples.

ICFP 2020
Justin Lubin, Nicholas Collins, Cyrus Omar, and Ravi Chugh

We are now working to scale up and integrate Smyth into the Hazel user interface, which requires considering the problems of interactivity, incrementality, and readability. Check out our first demo!

Relit: Reasonably Programmable Literal Notation

My thesis research developed mechanisms that allow library providers to express new type-specific literal notation (e.g. SQL literals) while ensuring that client programmers can still reason abstractly and compositionally about types and binding.

ICFP 2018
Cyrus Omar and Jonathan Aldrich
ECOOP 2014
Cyrus Omar, Darya Kurilova, Ligia Nistor, Benjamin Chung, Alex Potanin and Jonathan Aldrich
Distinguished Paper Award

Relit implements the mechanism from the ICFP 2018 paper into Reason, which is Facebook's new front-end for OCaml. The Wyvern programming language implements the mechanism from the ECOOP 2014 paper.

There has been a great deal of excitement around both Relit [1, 2, 3, 4, 5] and Wyvern [1, 2, 3, 4, 5]!

Graphite: Type-Specific Interactive Graphical Notation

We are working on mechanisms that allow you to define type-specific user interfaces that generate code underneath, i.e. they serve as interactive graphical notation. We have (1) implemented this mechanism for Java as an Eclipse extension called Graphite, (2) surveyed nearly 500 developers to empirically validate the mechanism and to gather a wide variety of use cases, and (3) performed a small pilot study.

ICSE 2012
Cyrus Omar, YoungSeok Yoon, Thomas D. LaToza and Brad A. Myers

We are now adding palettes with live holes to Hazel by combining this design with our ICFP 2018 and POPL 2019 work. We call these live literals, or livelits. Check out the slides from TyDe 2019.
Previous Publications & Projects

typy: Programmable Semantic Fragments

typy allows library providers to install new statically typed semantic fragments into Python, while leaving its syntax alone (which cleverly sidesteps the "expression problem"). We have applied typy to problems in web security and data science.

PSP 2014
Nathan Fulton, Cyrus Omar and Jonathan Aldrich
Best Paper Award

The typy implementation is quiet as I focus on my other projects, but if you want to take the lead, contact me!

SciUnit: Collaborative Infrastructure for Test-Driven Scientific Model Validation

One of the pillars of the scientific method is model validation: comparing a scientific model’s predictions against empirical data. The SciUnit project casts this as a form of collaborative software testing and develops useful infrastructure.

ICSE 2014
NIER Track
Cyrus Omar, Richard C. Gerkin and Jonathan Aldrich

My collaborators Rick Gerkin and Sharon Crook continue to develop and apply SciUnit as part of the SciDash project.

Neurobiological Circuit Dynamics

I entered grad school as a computational neurobiologist. I was interested in how biological circuits process information, so I developed a model of how the excitatory-inhibitory circuitry in the rodent whisker barrel cortex responds to stimulation.

J. Neurosci.
Jason W. Middleton, Cyrus Omar, Brent Doiron and Daniel J. Simons

I still find brains fascinating, but I think we will need more powerful computational tools to make the next leap in understanding, so now I study programming languages and programming environments!

Information Theoretic Foundations for Brain-Computer Interfaces

We built a provably optimal EEG-based brain-computer interface by studying the information theoretic properties of noisy asymmetric channels and developing statistical models of user intent for various types of communication/control tasks.

IJHCI 2011
BCI Issue
Cyrus Omar, Abdullah Akce, Miles Johnson, Timothy Bretl, Rui Ma, Edward Maclin, Michael McCormick and Todd Coleman

I remain very interested in building tools that help people with limited mobility and other disabilities express their intent. I also remain very interested in tastefully incorporating statistical models of user intent into programming environments.