Ben Lippmeier

email: benl (AT) ouroborus.net
freenode: benl23

(dblp profile)
(GitHub profile)
(misc code bin)
(Haskellers profile)
(Google Scholar profile)
(YouTube demo channel)

About Me

• I work at Ghost Locomotion in machine learning for self driving cars.
  
  
• I have previously worked at Digital Asset in smart contracts and programming language theory,
  as a private consultant in financial data processing,
  at the Commonwealth Bank of Australia in data science and machine learning,
  and as a lecturer at the University of Sydney and Australian National University
  and as a postdoc at the University of New South Wales.
  
  
• Most of my research and development is based around the Haskell family of languages.
  
  
• I am a regular at fp-syd.
  
  
• I have kept a variety of aquarium fish, though not always successfully.
  
  
• When I'm not doing the above I practice Aikido and Iaijutsu
  
  
• In a past life I studied electronics and communications engineering, before software ate the world.

Publications

• Smart Contracts as Authorized Production Rules
  PPDP 2019 (project github site)
  with Amos Robinson and Andrae Muys
  
  
• Machine Fusion: Merging merges, more or less
  PPDP 2017
  with Amos Robinson
  
  
• Polarized Data Parallel Data Flow
  FHPC 2016 (reference implementation)
  with Amos Robinson and Fil Mackay
  
  
• Icicle: write once, run once
  FHPC 2016
  with Amos Robinson
  
  
• Fusing Filters with Integer Linear Programming
  FHPC 2014 (slides),
  with Amos Robinson and Gabriele Keller.
  
  
• Data Flow Fusion with Series Expressions in Haskell
  Haskell 2013 (slides),
  with Manuel Chakravarty, Gabriele Keller and Amos Robinson.
  
  
• Optimising Purely Functional GPU Programs
  ICFP 2013
  with Trevor McDonell, Manuel Chakravarty and Gabriele Keller.
  
  
• Guiding Parallel Array Fusion with Indexed Types
  Haskell 2012 (slides), (video),
  with Manuel Chakravarty, Gabriele Keller and Simon Peyton Jones.
  
  
• Vectorisation Avoidance
  Haskell 2012
  with Gabriele Keller, Manuel Chakravarty, Roman Leshchinskiy and Simon Petyon Jones.
  
  
• Work Efficient Higher-Order Vectorisation
  ICFP 2012, (slides), (video), (tech report), (dph-reference-array.tgz),
  with Manuel Chakravarty, Gabriele Keller, Roman Leshchinskiy and Simon Peyton Jones.
  
  
• Efficient Parallel Stencil Convolution in Haskell
  Haskell 2011 (slides), (demo video),
  with Gabriele Keller.
  
  
• Regular, shape-polymorphic, parallel arrays in Haskell
  ICFP 2010, (slides),
  with Gabriele Keller, Manuel Chakravarty, Roman Leshchinskiy and Simon Peyton Jones.
  
  
• Type Inference and Optimisation for an Impure World
  ANU 2010 (PhD thesis)
  
  
• Witnessing Purity, Constancy and Mutability
  APLAS 2009 (slides),
  

Reports

• Don't Substitute into Abstractions
  (coq script and interpreter)
  
  
• Mechanized soundness for a type and effect system with region deallocation
  (coq script)
  
  
• An AMPLE Implementation
  Abstract Machine for Parallel Lazy Evaluation (AMPLE)
  with Clem Baker-Finch, 2003
  
  
• A High Temperature Superconducting Microwave Filter for the Narrabri Radio Telescope
  work done at the Australia Telescope National Facility (ATNF), 2001

Talks

• Types (are/want to be) Calling Conventions
  2019/5/14. LambdaJam
  2019/1/23. FP-Syd: Functional Programming Sydney
  
  
• Smart Contracts as Authorized Production Rules
  2019/4/26. FP-Syd: Functional Programming Sydney
  
  
• Machine Fusion is not Associative (or Commutative)
  2018/10/22. Shonan Meeting on Functional Stream Libraries and Fusion
  
  
• Polarized Data Parallel Data Flow
  2016/9/17. FHPC: Functional High Performance Computing
  
  
• Automatically Escaping Monads
  2017/2/08. HaskellZ: Zurich Haskell Meetup (slides) (video)
  2016/9/23. HIW: Functional Programming Sydney (slides) (video)
  
  
• Data Parallel Data Flow in Repa 4
  2015/5/22. LambdaJam
  2015/2/25. FP-Syd: Functional Programming Sydney
  
  
• Stream Fusion in Continuation Passing Style
  2014/12/09. SAWDAP: Sydney Area Workshop on Data Science and Programming Languages
  
  
• Query Fusion
  2014/10/03. Macquarie University
  
  
• Data Flow Fusion
  2014/10/03. CBA: Commonwealth Bank of Australia
  
  
• Flattening Nested Database Queries
  2014/05/28. FP-Syd: Functional Programming Sydney
  
  
• Capabilities and Coeffects
  2013/12/16. SAPLING: Sydney Area Programming Languages Interest Group
  
  

... more Talks

Projects

Gloss

Gloss hides the pain of drawing simple 2D graphics in Haskell behind a nice data structure and a couple of display functions. Used in 1st year CompSci at the ANU and UNSW. The library uses the GHC OpenGL binding, but you won't have to worry about any of that. Get something cool on the screen in under 10 minutes.

• (wiki) Development wiki
• (code) GitHub page
• (hacks) Hackage page

(source)

(source)

(source)

(source)

(source)

Repa

Repa is a Haskell library that provides high performance, regular, multi-dimensional, shape polymorphic parallel arrays. All numeric data is stored unboxed. Functions written with the Repa combinators are automatically parallel provided you supply +RTS -Nwhatever on the command line when running the program. Repa means "turnip" in Russian. If you don't like turnips then this library probably isn't for you.

• (wiki) Development Wiki
• (code) GitHub page
• (hacks) Hackage page
  
  
• (paper) Guiding Parallel Array Fusion with Indexed Types
• (paper) Efficient Parallel Stencil Convolution in Haskell
• (paper) Regular, shape-polymorphic, parallel arrays in Haskell
  
  
• (talk) Practical Parallel Array Fusion with Repa, LambdaJam 2013
• (talk) Practical Parallel Array Fusion with Repa (Workshop), LambdaJam 2013
• (talk) Efficient Parallel Stencil Convolution in Haskell, FP-SYD March 2011
• (talk) Regular Shape Polymorphic Parallel Arrays in Haskell, FP-SYD August 2010, ICFP September 2010

(wiki)

(wiki)

(blog post) (demo video)

... more Projects

Students

• Amos Robinson
  The stuff that streams are made of (PhD thesis, 2019)
  Rewrite Rules for the Disciplined Disciple Compiler (honours thesis, 2012)
  
  
• Chris Hall (2017 - 2019)
  Side-effect inference and control in modern imperative programming languages
  
  
• Hui (Matthew) Yu
  Combining garbage collection and region allocation in DDC (honours thesis, 2018)
  
  
• Michael Sproul
  A Library Based Approach to the Verification of Languages with Linear Types (honours thesis, 2016)
  
  
• Arthur Gan
  Raytracing Minecraft style octrees in parallel Haskell (honours thesis, 2013)
  
  
• Tran Ma
  Type Based Aliasing Control for the Disciplined Disciple Compiler (honours thesis, 2012)
  
  
• Ben Lambert-Smith
  A Parallel Fluid Flow Simulator in Haskell (honours thesis, 2011)

Events

• 2022: PC: ICFP
• 2021: PC: Haskell Reviewer: PLDI.
• 2020: AEC co-chair: ICFP.
• 2019: PC: IFL. AEC co-chair: ICFP.
• 2018: PC: PPDP.
• 2017: PC: ICFP.
• 2016: PC: FHPC. ERC: ICFP. Reviewer: SCICO.
• 2015: PC chair: Haskell. Reviewer: JFP.
• 2014: PC: FHPC, TFP. Reviewer: Haskell, ICFP, JFP.
• 2013: Reviewer: APLAS, FHPC, PEDS.
• 2012: PC: Haskell. Reviewer: ESOP JFP, TOPLAS.
• 2011: PC co-chair: HIW. Reviewer: HOSC, ICALP, JFP.
• 2010: PC: HIW. Reviewer: APLAS, PLDI.
• 2008: Reviewer: CC.

Teaching

• 2015: Programming Languages and Paradigms
• 2014: Programming Languages and Paradigms

• 2012: Advanced Algorithms (guest lecturer)
• 2010: Computing 1 (bonus lectures in Haskell)

• 2009: Principles of Programming Languages
• 2009: Relational Databases (query optimisation unit)
• 2009: Multicore Computing (supervised masters project group)
• 2008: Formal Methods for Software Engineering (lecturer for half of course)
• 2008: Relational Databases (lecturer for query optimisation)
• 2008: Data Structures and Algorithms I (Haskell unit)
• 2007: Data Structures and Algorithms I (Haskell unit)
• 2006: Introduction to Programming and Algorithms