research-article

Open access

Effects as capabilities: effect handlers and lightweight effect polymorphism

Authors:

Jonathan Immanuel Brachthäuser,

Philipp Schuster,

Klaus OstermannAuthors Info & Claims

Proceedings of the ACM on Programming Languages, Volume 4, Issue OOPSLA

Article No.: 126, Pages 1 - 30

https://doi.org/10.1145/3428194

Published: 13 November 2020 Publication History

Abstract

Effect handlers have recently gained popularity amongst programming language researchers. Existing type- and effect systems for effect handlers are often complicated and potentially hinder a wide-spread adoption.

We present the language Effekt with the goal to close the gap between research languages with effect handlers and languages for working programmers. The design of Effekt revolves around a different view of effects and effect types. Traditionally, effect types express which side effects a computation might have. In Effekt, effect types express which capabilities a computation requires from its context. While this new point in the design space of effect systems impedes reasoning about purity, we demonstrate that it simplifies the treatment of effect polymorphism and the related issues of effect parametricity and effect encapsulation. To guarantee effect safety, we separate functions from values and treat all functions as second-class. We define the semantics of Effekt as a translation to System Xi, a calculus in explicit capability-passing style.

Supplementary Material

Auxiliary Presentation Video (oopsla20main-p6-p-video.mp4)

Jonathan Brachthäuser presents the OOPSLA 20 paper "Effects as Capabilities: Effect Handlers and Lightweight Effect Polymorphism".

Download
833.18 MB

References

[1]

Henk P. Barendregt. 1992. Lambda Calculi with Types. In Handbook of Logic in Computer Science (vol. 2 ): Background: Computational Structures. Oxford University Press, New York, NY, USA, 117-309.

[2]

Andrej Bauer and Matija Pretnar. 2013. An efect system for algebraic efects and handlers. In International Conference on Algebra and Coalgebra in Computer Science. Springer, Berlin, Heidelberg, 1-16.

[3]

Andrej Bauer and Matija Pretnar. 2015. Programming with algebraic efects and handlers. Journal of Logical and Algebraic Methods in Programming 84, 1 ( 2015 ), 108-123.

[4]

Nick Benton, Chung-Kil Hur, Andrew J Kennedy, and Conor McBride. 2012. Strongly typed term representations in Coq. Journal of automated reasoning 49, 2 ( 2012 ), 141-159.

Digital Library

[5]

Dariusz Biernacki, Maciej Piróg, Piotr Polesiuk, and Filip Sieczkowski. 2017. Handle with Care: Relational Interpretation of Algebraic Efects and Handlers. Proc. ACM Program. Lang. 2, POPL, Article 8 ( Dec. 2017 ), 30 pages.

[6]

Dariusz Biernacki, Maciej Piróg, Piotr Polesiuk, and Filip Sieczkowski. 2019. Abstracting Algebraic Efects. Proc. ACM Program. Lang. 3, POPL, Article 6 ( Jan. 2019 ), 28 pages.

[7]

Dariusz Biernacki, Maciej Piróg, Piotr Polesiuk, and Filip Sieczkowski. 2020. Binders by Day, Labels by Night: Efect Instances via Lexically Scoped Handlers. In Proceedings of the Symposium on Principles of Programming Languages (to appear). ACM, New York, NY, USA.

Digital Library

[8]

Eli Bingham, Jonathan P. Chen, Martin Jankowiak, Fritz Obermeyer, Neeraj Pradhan, Theofanis Karaletsos, Rohit Singh, Paul Szerlip, Paul Horsfall, and Noah D. Goodman. 2019. Pyro: Deep Universal Probabilistic Programming. J. Mach. Learn. Res. 20, 1 (Jan. 2019 ), 973-978.

[9]

Jonathan Immanuel Brachthäuser and Philipp Schuster. 2017. Efekt: Extensible Algebraic Efects in Scala (Short Paper). In Proceedings of the International Symposium on Scala (Vancouver, BC, Canada). ACM, New York, NY, USA. https: //doi.org/10.1145/3136000.3136007

Digital Library

[10]

Jonathan Immanuel Brachthäuser, Philipp Schuster, and Klaus Ostermann. 2018. Efect Handlers for the Masses. Proc. ACM Program. Lang. 2, OOPSLA, Article 111 (Oct. 2018 ), 27 pages. https://doi.org/10.1145/3276481

Digital Library

[11]

Jonathan Immanuel Brachthäuser, Philipp Schuster, and Klaus Ostermann. 2020a. Efekt: Capability-Passing Style for Typeand Efect-safe, Extensible Efect Handlers in Scala. Journal of Functional Programming ( 2020 ). https://doi.org/10.1017/ S0956796820000027

[12]

Jonathan Immanuel Brachthäuser, Philipp Schuster, and Klaus Ostermann. 2020b. Efekt: Lightweight Efect Polymorphism for Handlers. Extended Technical Report. University of Tübingen, Germany. http://ps.informatik.uni-tuebingen.de/ publications/brachthaeuser20efekt.pdf.

[13]

Jonathan Immanuel Brachthäuser and Daan Leijen. 2019. Programming with Implicit Values, Functions, and Control. Technical Report MSR-TR-2019-7. Microsoft Research.

[14]

Edwin Brady. 2013. Idris, a general-purpose dependently typed programming language: Design and implementation. Journal of Functional Programming 23, 5 ( 2013 ), 552-593.

[15]

Lukas Convent, Sam Lindley, Conor McBride, and Craig McLaughlin. 2020. Doo Bee Doo Bee Doo. Journal of Functional Programming 30 ( 2020 ), e9. https://doi.org/10.1017/S0956796820000039

[16]

Olivier Danvy and Andrzej Filinski. 1989. A functional abstraction of typed contexts. DIKU Rapport 89 /12, DIKU, University of Copenhagen ( 1989 ).

[17]

Stephen Dolan, Spiros Eliopoulos, Daniel Hillerström, Anil Madhavapeddy, KC Sivaramakrishnan, and Leo White. 2017. Concurrent system programming with efect handlers. In Proceedings of the Symposium on Trends in Functional Programming. Springer LNCS 10788.

[18]

Stephen Dolan, Leo White, and Anil Madhavapeddy. 2014. Multicore OCaml. In OCaml Workshop.

[19]

Stephen Dolan, Leo White, KC Sivaramakrishnan, Jeremy Yallop, and Anil Madhavapeddy. 2015. Efective concurrency through algebraic efects. In OCaml Workshop.

[20]

R. Kent Dybvig, Simon L. Peyton Jones, and Amr Sabry. 2007. A monadic framework for delimited continuations. Journal of Functional Programming 17, 6 ( 2007 ), 687-730.

[21]

Richard A. Eisenberg, Joachim Breitner, and Simon Peyton Jones. 2018. Type Variables in Patterns. In Proceedings of the Haskell Symposium (St. Louis, MO, USA) ( Haskell 2018 ). Association for Computing Machinery, New York, NY, USA, 94-105. https://doi.org/10.1145/3242744.3242753

Digital Library

[22]

Matthias Felleisen. 1988. The Theory and Practice of First-class Prompts. In Proceedings of the Symposium on Principles of Programming Languages (San Diego, California, USA). ACM, New York, NY, USA, 180-190.

Digital Library

[23]

Carl A. Gunter, Didier Rémy, and Jon G. Riecke. 1995. A Generalization of Exceptions and Control in ML-like Languages. In Proceedings of the Conference on Functional Programming Languages and Computer Architecture (La Jolla, California, USA). ACM, New York, NY, USA, 12-23.

[24]

Daniel Hillerström and Sam Lindley. 2016. Liberating Efects with Rows and Handlers. In Proceedings of the Workshop on Type-Driven Development (Nara, Japan). ACM, New York, NY, USA.

Digital Library

[25]

Daniel Hillerström, Sam Lindley, Bob Atkey, and KC Sivaramakrishnan. 2017. Continuation Passing Style for Efect Handlers. In Formal Structures for Computation and Deduction (LIPIcs, Vol. 84 ). Schloss Dagstuhl-Leibniz-Zentrum für Informatik.

[26]

Ohad Kammar, Sam Lindley, and Nicolas Oury. 2013. Handlers in Action. In Proceedings of the International Conference on Functional Programming (Boston, Massachusetts, USA). ACM, New York, NY, USA, 145-158.

Digital Library

[27]

Oleg Kiselyov, Chung-chieh Shan, and Amr Sabry. 2006. Delimited Dynamic Binding. In Proceedings of the International Conference on Functional Programming (Portland, Oregon, USA). ACM, New York, NY, USA, 26-37.

Digital Library

[28]

Daan Leijen. 2005. Extensible records with scoped labels. In Proceedings of the Symposium on Trends in Functional Programming. 297-312.

[29]

Daan Leijen. 2014. Koka: Programming with Row Polymorphic Efect Types. In Proceedings of the Workshop on Mathematically Structured Functional Programming.

[30]

Daan Leijen. 2016. Algebraic Efects for Functional Programming. Technical Report. MSR-TR-2016-29. Microsoft Research technical report.

[31]

Daan Leijen. 2017a. Structured Asynchrony with Algebraic Efects. In Proceedings of the Workshop on Type-Driven Development (Oxford, UK). ACM, New York, NY, USA, 16-29.

[32]

Daan Leijen. 2017b. Type directed compilation of row-typed algebraic efects. In Proceedings of the Symposium on Principles of Programming Languages. ACM, New York, NY, USA, 486-499.

[33]

Daan Leijen. 2018a. Algebraic Efect Handlers with Resources and Deep Finalization. Technical Report MSR-TR-2018-10. Microsoft Research. 35 pages.

[34]

Daan Leijen. 2018b. First Class Dynamic Efect Handlers: Or, Polymorphic Heaps with Dynamic Efect Handlers. In Proceedings of the Workshop on Type-Driven Development (St. Louis, Missouri, USA). ACM, New York, NY, USA, 51-64.

[35]

Paul Blain Levy, John Power, and Hayo Thielecke. 2003. Modelling environments in call-by-value programming languages. Information and Computation 185, 2 ( 2003 ), 182-210.

[36]

Sam Lindley, Conor McBride, and Craig McLaughlin. 2017. Do Be Do Be Do. In Proceedings of the Symposium on Principles of Programming Languages (Paris, France). ACM, New York, NY, USA, 500-514.

Digital Library

[37]

Jirka Maršík and Maxime Amblard. 2016. Introducing a Calculus of Efects and Handlers for Natural Language Semantics. In International Conference on Formal Grammar. Springer LNCS 9804, 257-272.

[38]

Andrey Mokhov, Neil Mitchell, and Simon Peyton Jones. 2018. Build Systems à La Carte. Proc. ACM Program. Lang. 2, ICFP, Article 79 ( July 2018 ), 29 pages. https://doi.org/10.1145/3236774

Digital Library

[39]

Dave Moore and Maria Ivanova Gorinova. 2018. Efect Handling for Composable Program Transformations in Edward2. In International Conference on Probabilistic Programming (PROBPROG).

[40]

Dereck C Oppen. 1980. Prettyprinting. Transactions on Programming Languages and Systems 2, 4 ( 1980 ), 465-483.

Digital Library

[41]

Leo Osvald, Grégory Essertel, Xilun Wu, Lilliam I González Alayón, and Tiark Rompf. 2016. Gentrification gone too far? afordable 2nd-class values for fun and (co-) efect. In Proceedings of the Conference on Object-Oriented Programming, Systems, Languages and Applications. ACM, New York, NY, USA, 234-251.

[42]

Tomas Petricek, Dominic Orchard, and Alan Mycroft. 2014. Coefects: A Calculus of Context-Dependent Computation. In Proceedings of the International Conference on Functional Programming (Gothenburg, Sweden). ACM, New York, NY, USA, 123-135. https://doi.org/10.1145/2628136.2628160

Digital Library

[43]

Du Phan, Neeraj Pradhan, and Martin Jankowiak. 2019. Composable efects for flexible and accelerated probabilistic programming in NumPyro. arXiv preprint arXiv: 1912. 11554 ( 2019 ).

[44]

Gordon D. Plotkin and Matija Pretnar. 2013. Handling Algebraic Efects. Logical Methods in Computer Science 9, 4 ( 2013 ).

[45]

Matija Pretnar. 2015. An introduction to algebraic efects and handlers. invited tutorial paper. Electronic Notes in Theoretical Computer Science 319 ( 2015 ), 19-35.

[46]

Lukas Rytz, Martin Odersky, and Philipp Haller. 2012. Lightweight Polymorphic Efects. In Proceedings of the European Conference on Object-Oriented Programming, James Noble (Ed.). Springer Berlin Heidelberg, Berlin, Heidelberg, 258-282.

[47]

Philipp Schuster and Jonathan Immanuel Brachthäuser. 2018. Typing, Representing, and Abstracting Control. In Proceedings of the Workshop on Type-Driven Development (St. Louis, Missouri, USA). ACM, New York, NY, USA, 14-24. https: //doi.org/10.1145/3240719.3241788

Digital Library

[48]

Philipp Schuster, Jonathan Immanuel Brachthäuser, and Klaus Ostermann. 2020. Compiling Efect Handlers in CapabilityPassing Style. 4, ICFP, Article 93 ( Aug. 2020 ), 28 pages. https://doi.org/10.1145/3408975

Digital Library

[49]

Dorai Sitaram. 1993. Handling Control. In Proceedings of the Conference on Programming Language Design and Implementation (Albuquerque, New Mexico, USA). ACM, New York, NY, USA, 147-155.

[50]

S Doaitse Swierstra and Olaf Chitil. 2009. Linear, bounded, functional pretty-printing. Journal of Functional Programming 19, 01 ( 2009 ), 1-16.

[51]

Fei Wang, Daniel Zheng, James Decker, Xilun Wu, Grégory M. Essertel, and Tiark Rompf. 2019. Demystifying Diferentiable Programming: Shift/Reset the Penultimate Backpropagator. Proc. ACM Program. Lang. 3, ICFP, Article 96 ( July 2019 ), 31 pages.

[52]

Andrew K. Wright and Matthias Felleisen. 1994. A syntactic approach to type soundness. Inf. Comput. 115, 1 (Nov. 1994 ), 38-94.

Digital Library

[53]

Nicolas Wu, Tom Schrijvers, and Ralf Hinze. 2014. Efect Handlers in Scope. In Proceedings of the Haskell Symposium (Gothenburg, Sweden) (Haskell '14). ACM, New York, NY, USA, 1-12.

[54]

Ningning Xie, Jonathan Immanuel Brachthäuser, Daniel Hillerström, Philipp Schuster, and Daan Leijen. 2020. Efect Handlers, Evidently. 4, ICFP, Article 99 ( Aug. 2020 ), 29 pages. https://doi.org/10.1145/3408981

Digital Library

[55]

Jeremy Yallop. 2017. Staged Generic Programming. Proc. ACM Program. Lang. 1, ICFP, Article 29 ( Aug. 2017 ), 29 pages.

Digital Library

[56]

Yizhou Zhang and Andrew C. Myers. 2019. Abstraction-safe Efect Handlers via Tunneling. Proc. ACM Program. Lang. 3, POPL, Article 5 ( Jan. 2019 ), 29 pages.

[57]

Yizhou Zhang, Guido Salvaneschi, Quinn Beightol, Barbara Liskov, and Andrew C. Myers. 2016. Accepting Blame for Safe Tunneled Exceptions. In Proceedings of the Conference on Programming Language Design and Implementation (Santa Barbara, CA, USA). ACM, New York, NY, USA, 281-295.

Cited By

Song YFoo DChin W(2024)Specification and Verification for Unrestricted Algebraic Effects and HandlingProceedings of the ACM on Programming Languages10.1145/36746568:ICFP(909-937)Online publication date: 15-Aug-2024
https://dl.acm.org/doi/10.1145/3674656
Xie NJohnson DMaclaurin DPaszke A(2024)Parallel Algebraic Effect HandlersProceedings of the ACM on Programming Languages10.1145/36746518:ICFP(756-788)Online publication date: 15-Aug-2024
https://dl.acm.org/doi/10.1145/3674651
Yoshioka TSekiyama TIgarashi A(2024)Abstracting Effect Systems for Algebraic Effect HandlersProceedings of the ACM on Programming Languages10.1145/36746418:ICFP(455-484)Online publication date: 15-Aug-2024
https://dl.acm.org/doi/10.1145/3674641
Show More Cited By

Index Terms

Effects as capabilities: effect handlers and lightweight effect polymorphism
1. Software and its engineering
  1. Software notations and tools
    1. General programming languages
      1. Language features
        Control structures
  2. Software organization and properties
    1. Software system structures
      1. Abstraction, modeling and modularity
2. Theory of computation
  1. Logic
    1. Type theory

Recommendations

Effect handlers for the masses

Effect handlers are a program structuring paradigm with rising popularity in the functional programming language community and can express many advanced control flow abstractions. We present the first implementation of effect handlers for Java - an ...
First-class names for effect handlers

Algebraic effects and handlers are a promising technique for incorporating composable computational effects into functional programming languages. Effect handlers enable concisely programming with different effects, but they do not offer a convenient way ...
Liberating effects with rows and handlers
TyDe 2016: Proceedings of the 1st International Workshop on Type-Driven Development

Algebraic effects and effect handlers provide a modular abstraction for effectful programming. They support user-defined effects, as in Haskell, in conjunction with direct-style effectful programming, as in ML. They also present a structured interface ...

Comments

Information & Contributors

Information

Published In

cover image Proceedings of the ACM on Programming Languages

Proceedings of the ACM on Programming Languages Volume 4, Issue OOPSLA

November 2020

3108 pages

EISSN:2475-1421

DOI:10.1145/3436718

Issue’s Table of Contents

Copyright © 2020 Owner/Author.

This work is licensed under a Creative Commons Attribution-NoDerivatives International 4.0 License.

Publisher

Association for Computing Machinery

New York, NY, United States

Publication History

Published: 13 November 2020

Published in PACMPL Volume 4, Issue OOPSLA

Permissions

Request permissions for this article.

Request Permissions

Check for updates

Badges

Author Tags

Qualifiers

Research-article

Funding Sources

DFG

Contributors

Other Metrics

View Article Metrics

Bibliometrics & Citations

Bibliometrics

Article Metrics

38
Total Citations
View Citations
2,713
Total Downloads

Downloads (Last 12 months)765
Downloads (Last 6 weeks)70

Reflects downloads up to 11 Aug 2024

Other Metrics

View Author Metrics

Citations

Cited By

Song YFoo DChin W(2024)Specification and Verification for Unrestricted Algebraic Effects and HandlingProceedings of the ACM on Programming Languages10.1145/36746568:ICFP(909-937)Online publication date: 15-Aug-2024
https://dl.acm.org/doi/10.1145/3674656
Xie NJohnson DMaclaurin DPaszke A(2024)Parallel Algebraic Effect HandlersProceedings of the ACM on Programming Languages10.1145/36746518:ICFP(756-788)Online publication date: 15-Aug-2024
https://dl.acm.org/doi/10.1145/3674651
Yoshioka TSekiyama TIgarashi A(2024)Abstracting Effect Systems for Algebraic Effect HandlersProceedings of the ACM on Programming Languages10.1145/36746418:ICFP(455-484)Online publication date: 15-Aug-2024
https://dl.acm.org/doi/10.1145/3674641
Binder DTzschentke MMüller MOstermann K(2024)Grokking the Sequent Calculus (Functional Pearl)Proceedings of the ACM on Programming Languages10.1145/36746398:ICFP(395-425)Online publication date: 15-Aug-2024
https://dl.acm.org/doi/10.1145/3674639
Xu YBoruch-Gruszecki AOdersky M(2024)Degrees of Separation: A Flexible Type System for Safe ConcurrencyProceedings of the ACM on Programming Languages10.1145/36498538:OOPSLA1(1181-1207)Online publication date: 29-Apr-2024
https://doi.org/10.1145/3649853
Elsman M(2024)Explicit Effects and Effect Constraints in ReMLProceedings of the ACM on Programming Languages10.1145/36329218:POPL(2370-2394)Online publication date: 5-Jan-2024
https://dl.acm.org/doi/10.1145/3632921
Andrici CCiobâcă ȘHriţcu CMartínez GRivas ETanter ÉWinterhalter T(2024)Securing Verified IO Programs Against Unverified Code in F*Proceedings of the ACM on Programming Languages10.1145/36329168:POPL(2226-2259)Online publication date: 5-Jan-2024
https://dl.acm.org/doi/10.1145/3632916
Tang WHillerström DLindley SMorris J(2024)Soundly Handling LinearityProceedings of the ACM on Programming Languages10.1145/36328968:POPL(1600-1628)Online publication date: 5-Jan-2024
https://dl.acm.org/doi/10.1145/3632896
HILLERSTRÖM DLINDLEY SLONGLEY J(2024)Asymptotic speedup via effect handlersJournal of Functional Programming10.1017/S095679682400003034Online publication date: 5-Apr-2024
https://doi.org/10.1017/S0956796824000030
van den Berg BSchrijvers T(2024)A framework for higher-order effects & handlersScience of Computer Programming10.1016/j.scico.2024.103086234:COnline publication date: 1-May-2024
https://dl.acm.org/doi/10.1016/j.scico.2024.103086
Show More Cited By

View Options

View options

PDF

View or Download as a PDF file.

eReader

View online with eReader.

Get Access

Login options

Check if you have access through your login credentials or your institution to get full access on this article.

Full Access

Get this Article

Media

Figures

Other

Tables

View Issue’s Table of Contents