Galois › Blog » Haskell

Entries in the “Haskell” category

Tech Talk Video: abcBridge: Functional interfaces for AIGs and SAT solving

August 27th, 2010 by Iavor S. Diatchki

We are pleased to announce the availability of a new Galois tech talk video: “abcBridge: Functional interfaces for AIGs and SAT solving”, presented by Edward Z. Yang . More details about the talk are available on the announcement page.

abcBridge: Functional Interfaces for AIGs & SAT Solving from Galois Video on Vimeo.

For more videos, please visit http://vimeo.com/channels/galois.

Posted in Formal Methods, Functional Programming, Haskell, Tech Talks, Video | Comments (0)

Tech talk: abcBridge: Functional interfaces for AIGs and SAT solving

August 19th, 2010 by Iavor S. Diatchki

Galois is pleased to host the following tech talk. These talks are open to the interested public. Please join us!

title:

abcBridge: Functional interfaces for AIGs and SAT solving (slides, video)

presenter:

Edward Z. Yang

time:

10:30am, Tuesday, 24 August 2010

location:

Galois Inc.
421 SW 6th Ave. Suite 300, Portland, OR, USA
(3rd floor of the Commonwealth building)

abstract:

SAT solvers are perhaps the most under-utilized high-tech tools that the modern software engineer has at their fingertips. An industrial strength SAT solver can solve most human generated NP-complete problems in time for lunch, and there are many, many practical problem domains which involve NP-complete problems. However, a major roadblock to using a SAT solver in your every day routine is translating your problem into SAT, and then running it on a highly optimized SAT solver, which is probably implemented in C or C++ and not your usual favorite programming language.

This talk is about the use, design and implementation of abcBridge, a set of Haskell bindings for ABC, a system for sequential synthesis and verification produced by the Berkeley Logic Synthesis and Verification Group. ABC looks at SAT solving from the following perspective: given two circuits of logic gates (ANDs and NOTs), are they equivalent? ABC is imperative C code: abcBridge provides a pure and type-safe interface for building and manipulating and-inverter graphs. We hope to release abcBridge soon as open source.

bio:

Edward Z. Yang is an undergraduate studying computer science at MIT. He has been interning at Galois over the summer and enjoying every second of it. His interests include blogging, functional programming and practical applications of computer science research. You can read his blog at http://blog.ezyang.com/

Posted in Formal Methods, Functional Programming, Haskell, Open Source, Tech Talks | Comments (0)

Tech Talk Video: Developing Good Habits for Bare-Metal Programming

August 11th, 2010 by Iavor S. Diatchki

We are pleased to announce the availability of a new Galois tech talk video: “Developing Good Habits for Bare-Metal Programming”, presented by Mark Jones. More details about the talk are available on the announcement page.

Developing Good Habits for Bare-Metal Programming from Galois Video on Vimeo.

For more videos, please visit http://vimeo.com/channels/galois.

Posted in Functional Programming, Haskell, Tech Talks, Technology, Video | Comments (0)

Orc in Haskell, now on Hackage

June 14th, 2010 by john

Orc is a concurrent scripting language, now available as an embedded DSL in Haskell. I like to think of Orc as the combination of three things: many-valued concurrency, external actions (effects), and managed resources, all packaged in a high-level set of abstractions that feel more like scripting rather than programming. It provides a very flexible way to manage multiple concurrent actions, like querying remote web sites, along with timeouts and default actions.

Source code is available on Hackage; the easiest way to access it is with cabal (i.e. ‘cabal install orc’).

Also available is a draft paper entitled Concurrent Orchestration in Haskell which explains how to use Orc, as well as describing the implementation in detail.

Feedback welcome. Enjoy!

Posted in Functional Programming, Haskell | Comments (1)

Tech Talk: Developing Good Habits for Bare-Metal Programming

May 12th, 2010 by Iavor S. Diatchki

Galois is pleased to host the following tech talk. These talks are open to the interested public. Please join us!

title: Developing Good Habits for Bare-Metal Programming (slides, video)
presenter: Mark Jones; High Assurance Systems Programming Project (HASP); Portland State University
time: 10:30am, Tuesday, 18 May 2010
location: Galois Inc.
421 SW 6th Ave. Suite 300, Portland, OR, USA
(3rd floor of the Commonwealth building)
abstract: Developers of systems software must often deal with low-level and performance-critical details that are hard to address in high-level programming languages. As a result, much of the systems software that is produced today is written in languages like C and assembly code, without the benefit of more expressive type systems or other features from modern functional programming languages that could help to increase programmer productivity or software quality. In this talk, we present an update on the status of Habit, a dialect of Haskell that we are designing, as part of the HASP project at PSU, to meet the needs of high assurance systems programming. Among other features, Habit provides: mechanisms for fine control over representation of bit-level and memory-based data structures; strong support for both functional and imperative programming; and a flexible type system that allows precise characterization of size and bound information via type level naturals, as well as termination properties resulting from the use of unpointed types.
bio: (from http://web.cecs.pdx.edu/~mpj/)
Mark Jones is a Professor in the Department of Computer Science in the Maseeh College of Engineering & Computer Science at Portland State University in Portland, Oregon, USA. His interests include all aspects of programming language design, implementation, and application. He is particularly interested in the use of advanced programming language technologies for systems programming, and in the development and application of expressive type and module systems that support the construction and certification of secure and reliable software systems.

Posted in Formal Methods, Functional Programming, Haskell, Tech Talks, Technology | Comments (2)

Tech Talk: Typing Directories

April 30th, 2010 by Lee Pike

Galois is pleased to host the following tech talk. These talks are open to the interested public. Please join us!

The talk will be held at

Galois Inc.
421 SW 6th Ave. Suite 300, Portland, OR, USA
(3rd floor of the Commonwealth building)

Typing Directories

Details:

Presenter: Kathleen Fisher, AT&T Labs
Date: Monday May 03, 2010
Time: 3:30pm (NOTE THE CHANGED DATE AND TIME!)

Abstract: PADS describes the contents of individual ad hoc data files, but has no provisions for describing collections of files, i.e., directories. In this talk, I explore examples where having a declarative description of directories as well as files would be useful, including websites, source code trees, source code control systems, operating systems, and scientific data sets. As part of this exploration, I identify essential features of a directory description language and useful tools that might be produced from such a description. I end with a series of questions about how such a language might most easily be implemented in the context of Haskell.

This is joint work with David Walker and Kenny Zhu.

Bio: (from http://www.research.att.com/people/Fisher_Kathleen_S) Kathleen Fisher is a Principal Member of the Technical Staff at AT&T Labs Research and a Consulting Faculty Member in the Computer Science Department at Stanford University. Kathleen’s research focuses on advancing the theory and practice of programming languages and on applying ideas from the programming language community to the problem of ad hoc data management. The main thrust of her work has been in domain-specific languages to facilitate programming with massive amounts of ad hoc data, including the Hancock system for efficiently building signatures from massive transaction streams and the PADS system for managing ad hoc data.

Kathleen is an ACM Distinguished Scientist. She has served as program chair for FOOL, CUFP, and ICFP. She is past Chair of the ACM Special Interest Group in Programming Languages (SIGPLAN), Co-Chair of CRA’s Committee on the Status of Women (CRA-W), and an editor of the Journal of Functional Programming. She is currently serving on the CRA Board.

Posted in Haskell, Tech Talks | Comments (0)

Tech Talk: Two Talks! One Week!

March 20th, 2010 by Lee Pike

LATE NOTICE: The Simon Thompson talk has been moved to Thurs. April 1, at 10:30am.

Please note the non-standard times for these talks.

Galois is pleased to host two tech talks during the week of March 22, 2010. The two talks are short (20-30 minutes each) talks back-to-back at 10:30am on March 24th. Details are below.

Talks will be held at

Galois Inc.
421 SW 6th Ave. Suite 300, Portland, OR, USA
(3rd floor of the Commonwealth building)

These talks are open to the interested public. Please join us!

Visualization and Diversity Information

Details:

Presenter: Prof. Ron Metoyer
Date: Wednesday, March 24, 2010
Time: 10:30am

Abstract: The term “diversity’’ is used in many ways in many domains. People are concerned about the diversity of their work force, stock portfolios, student body, and forest insects, just to name a few. In this talk, I will discuss a work-in-progress visualization technique specifically designed to communicate diversity information. I will present the design concerns, resulting visualizations, and a study design for evaluating the method. I will conclude with a discussion of a case-study application to moth species data.

Bio: Ronald Metoyer is an Associate Professor in the School of Electrical Engineering and Computer Science at Oregon State University. He earned a Ph.D. from the Georgia Institute of Technology where he worked in the Graphics, Visualization and Usability Center with a focus on modeling and visualizing the motion of pedestrians in urban and architectural scenes. Dr. Metoyer currently co-directs the NVIDIA Graphics and Imaging Technologies Lab (GAIT) with his colleagues at OSU. His past research efforts have involved the investigation of techniques for manipulating motion capture data and for facilitating the creation of 3D content by end users with the goal of empowering domain experts to create compelling and interactive content for their domain specific needs. In 2002, he received an NSF CAREER Award for his work in “Understanding the Complexities of Animated Content”. Dr. Metoyer’s most recent research interests fall under the domain of information visualization.

TITLE: Scientific Data Visualization in a GPU World

Details:

Presenter: Prof. Mike Bailey
Date: Wednesday, March 24, 2010
Time: 11:00am

Abstract: One of the fun aspects of scientific data visualization is that there are no rules — anything that adds insight to the data display is fair game. Add that to the fun of custom-programming the GPU, and you’ve really got something!

This talk will discuss some of the uses of custom GPU programming to create better and more interactive visualization displays. We will look at techniques in the realm of scalar visualization, vector visualization, volume visualization, and terrain mapping.

Bio: Mike Bailey is a Professor in Computer Science at Oregon State University. He specializes in scientific visualization, 3D interactive computer graphics, GPU programming, stereographics, and computer aided geometric design.

Posted in Community, Functional Programming, Haskell, Tech Talks | Comments (0)

Tech Talk: An Introduction to Communicating Haskell Processes

March 10th, 2010 by Iavor S. Diatchki

Please note the unusual time-slot for this talk!

Details:

Title: An Introduction to Communicating Haskell Processes
Presenter: Neil Brown
Date: Monday, 15 March 2010
Time: 10:30am
Location: Galois Inc.
421 SW 6th Ave. Suite 300, Portland, OR, USA
(3rd floor of the Commonwealth building)

Abstract: Haskell is an excellent language for combining the power of functional programming with imperative constructs. This characteristic led to the development of the Communicating Haskell Processes (CHP) libraries, which support imperative synchronous message-passing in Haskell. The core ‘chp’ library provides basic message-passing, concurrency and choice, as well as integrated support for tracing. The ‘chp-plus’ library provides higher-level features such as process composition operators and behaviour combinators. This talk provides an introduction to the two libraries and the programming style they engender — as well as a brief look at the formal semantics underlying the libraries.

Bio: Neil Brown is a software researcher from the University of Kent in the UK. After graduating he worked for several years as a machine learning researcher in industry at QinetiQ, before returning to university to undertake his PhD. He started out writing a Haskell-based compiler for synchronous message-passing languages, and ended up programming some synchronous message-passing libraries for Haskell itself. As well as these CHP libraries, he also developed the Progression benchmark-graphing library for Haskell. More detail on both projects can be found on his blog.

Posted in Functional Programming, Haskell, Open Source, Tech Talks | Comments (1)

Tech Talk: Modern Benchmarking in Haskell

February 19th, 2010 by Iavor S. Diatchki

Details:

Title: Modern Benchmarking in Haskell (slides)
Presenter: Don Stewart
Date: Tuesday, 23 February 2010
Time: 10:30am
Location: Galois Inc.
421 SW 6th Ave. Suite 300, Portland, OR, USA
(3rd floor of the Commonwealth building)

Abstract: Thanks to work by Bryan O’Sullivan, there has been a renaissance in performance benchmarking tools for Haskell, built upon Criterion.

“Compared to most other benchmarking frameworks (for any programming language, not just Haskell), criterion focuses on being easy to use, informative, and robust.”

Criterion uses statistically robust mechanisms for sampling and computing sound microbenchmark results, and is more stable in the presence of noise on the system than naive timings.

Criterion has in turn spawned some extensions:

Progrssion: compare different criterion graphs
NoSlow: a new array benchmark suite based on Criterion

In this talk I will present these tools, how to use them, and how to make your performance benchmarks in Haskell, or languages Haskell can talk to, more reliable.

Bio: Don is an Australian open source hacker, and engineer at Galois, Inc, in Portland, Oregon, where he works on creating trustworthiness and assurance in critical systems with an emphasis on language design and compiler techniques. Don is co-author of the book, Real World Haskell, published by O’Reilly, and the XMonad window manager.

Galois has been holding weekly technical seminars for several years on topics from functional programming, formal methods, compiler and language design, to cryptography, and operating system construction, with talks by many figures from the programming language and formal methods communities. The talks are open and free. An RSVP is not required, but feel free to contact the organizer with questions and comments.

Posted in Haskell, Open Source, Tech Talks | Comments (1)

Tech Talk: Introduction to Aarne Ranta’s GF, the Grammatical Framework

February 11th, 2010 by Lee Pike

The talk will be presented by Iavor Diatchki on Tuesday, February 16th, at 10:30am.

(slides)
Abstract: The Grammatical Framework (created by Aarne Ranta) is a programming language for multilingual grammar applications. It may be seen in a number of different ways:

as a special-purpose language for grammars, like YACC or Happy, but not restricted to programming languages;
as a functional language, like Haskell or SML, but specialized to grammar writing;
as a logical framework, like Agda or Coq, but equipped with concrete syntax in addition to logic;
as a natural language processing framework, like LKB, or Regulus, but based on functional programming and type theory.

This talk is an introduction to GF’s basic concepts by example. We will look at how to define the meaning and syntax of a language, perform simple translations, define semantic properties, and how to use GF together with another language such as Haskell.

Bio: Iavor Diatchki is a R&D Engineer at Galois, Inc. with a Ph.D. from the Oregon Graduate Institute.

Details:

Date: February 16th, 2010, Tuesday
Time: 10:30am
Location: Galois Inc., 421 SW 6th Ave. Suite 300 (3rd floor of the Commonwealth building)

Posted in Community, Functional Programming, Haskell, Tech Talks | Comments (2)