About

I am a Ph.D. student in the Programming Language Group at HKU, advised by Prof. Bruno Oliveira. Before that, I obtained my B.S. (with Honors) from Zhejiang Unversity.
I had the pleasure to work with Richard Eisenberg over Summer 2018, and Tom Schrijvers over Spring 2018.
I spent my Summer 2019 with the Google Search Team in New York City.
I am currently working with Daan Leijen at Microsoft Research, Redmond.

News

• 2020 May New paper Effect Handlers, Evidently conditionally accepted at ICFP 2020. Preprint coming soon.

• 2020 Apr New paper Row and Bounded Polymorphism via Disjoint Polymorphism accepted at ECOOP 2020.

• 2020 Jan Presented Kind Inference for Datatypes on POPL 2020.

• 2020 Jan Started an internship at Microsoft Research Redmond.

• 2019 Dec Will serve on Artifact Evaluation Committee of PLDI 2020.

• 2019 Dec Our Kind Inference for Datatypes work won POPL Distinguished Paper Award

Publications

• Effect Handlers, Evidently. [preprint]
  Ningning Xie, Jonathan Brachthäuser, Daniel Hillerström, Philipp Schuster, Daan Leijen
  Conditionally accepted at 25th International Conference on Functional Programming (ICFP 2020)

• Row and Bounded Polymorphism via Disjoint Polymorphism. [preprint] [appendix] [artifact]
  Ningning Xie, Bruno C. d. S. Oliveira, Xuan Bi, Tom Schrijvers
  34th European Conference on Object-Oriented Programming (ECOOP 2020)

• Kind Inference for Datatypes. [paper] [slides] [appendix]
  Ningning Xie, Richard A. Eisenberg, Bruno C. d. S. Oliveira
  47th Symposium on Principles of Programming Languages (POPL 2020)
  ACM SIGPLAN Distinguished Paper Award

• Consistent Subtyping for All. [paper] [artifact]
  Ningning Xie, Xuan Bi, Bruno C. d. S. Oliveira, Tom Schrijvers
  ACM Transactions on Programming Languages and Systems (TOPLAS)
  Special Issue on ESOP 2018
  

• Distributive Disjoint Polymorphism for Compositional Programming. [paper] [slides] [artifact] [poster]
  Xuan Bi, Ningning Xie, Bruno C. d. S. Oliveira, Tom Schrijvers
  28th European Symposium on Programming (ESOP 2019)

• Coherence of Type Class Resolution. [paper] [appendix]
  Gert-Jan Bottu, Ningning Xie, Koar Marntirosian, Tom Schrijvers
  24th International Conference on Functional Programming (ICFP 2019)

• Let Arguments Go First. [paper] [slides] [artifact]
  Ningning Xie, Bruno C. d. S. Oliveira
  27th European Symposium on Programming (ESOP 2018)

• Consistent Subtyping for All. [paper] [artifact]
  Ningning Xie, Xuan Bi, Bruno C. d. S. Oliveira
  27th European Symposium on Programming (ESOP 2018)

Extended Abstract

• Coercion Quantification. [extended abstract] [slides]
  Ningning Xie, Richard A. Eisenberg
  10th Haskell Implementors' Workshop (HIW 2018)

• Towards Unification for Dependent Types. [extended abstract] [slides]
  Ningning Xie, Bruno C. d. S. Oliveira
  18th Symposium on Trends in Functional Programming (TFP 2017)

Talks

• Inferring Datatypes [slides]
  Lightning talk. 11th Haskell Implementors' Workshop (HIW 2019). Berlin, Germany. August 23, 2019.

• Dependent Types in Haskell. [slides] [code]
  Hong Kong Functional Programming Meetup. Hong Kong. December 13, 2018.

• Consistent Subtyping for All. [slides]
  Penn PLClub. University of Pennsylvania, Philadelphia, PA, USA. May 11, 2018.

Service

• Artifact Evaluation Committee. PLDI 2020.
• Program Committee. Haskell Implementors' Workshop 2019.
• Program Committee. Haskell Symposium 2019.
• Artifact Evaluation Committee. ICFP 2019.
• Sub-Reviewer. APLAS 2016, 2017. ESOP 2017. FLOPS 2018. ECOOP 2019. ICFP 2019.
• Student Volunteer. APSys 2016. PLDI 2018. ICFP 2018. ETAPS 2019.

Teaching

• Instructor. Haskell 101 NYC. Google, New York City. November 2019.
• Teaching Assistant. Principles of Programming Languages. The University of Hong Kong. Spring 2019.
• Teaching Assistant. Functional Programming. The University of Hong Kong. Fall 2017.

Miscellany

• Literature Review of GHC Core. In The GHC Commentary. June 2018.
• Voluntary Translator. Software Foundations, Chinese edition.