A talk about scope graphs at Curry On 2017 in Barcelona

Talk by Casper Bach Poulsen at ECOOP 2016 about the paper:

Casper Bach Poulsen, Pierre Néron, Andrew P. Tolmach, Eelco Visser. Scopes Describe Frames: A Uniform Model for Memory Layout in Dynamic Semantics. In Shriram Krishnamurthi, Benjamin S. Lerner, editors, 30th European Conference on Object-Oriented Programming, ECOOP 2016, July 18-22, 2016, Rome, Italy. Volume 56 of LIPIcs, Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2016. [PDF] [researchr]

Abstract: Semantic specifications do not make a systematic connection between the names and scopes in the static structure of a program and memory layout, and access during its execution. In this paper, we introduce a systematic approach to the alignment of names in static semantics and memory in dynamic semantics, building on the scope graph framework for name resolution. We develop a uniform memory model consisting of frames that instantiate the scopes in the scope graph of a program. This provides a language-independent correspondence between static scopes and run-time memory layout, and between static resolution paths and run-time memory access paths. The approach scales to a range of binding features, supports straightforward type soundness proofs, and provides the basis for a language-independent specification of sound reachability-based garbage collection.

Talk by Daco Harkes at ECOOP 2016 about the paper:

Daco Harkes, Danny M. Groenewegen, Eelco Visser. IceDust: Incremental and Eventual Computation of Derived Values in Persistent Object Graphs. In Shriram Krishnamurthi, Benjamin S. Lerner, editors, 30th European Conference on Object-Oriented Programming, ECOOP 2016, July 18-22, 2016, Rome, Italy. Volume 56 of LIPIcs, Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2016.b [doi]

Abstract: Derived values are values calculated from base values. They can be expressed in object-oriented languages by means of getters calculating the derived value, and in relational or logic databases by means of (materialized) views. However, switching to a different calculation strategy (for example caching) in object-oriented programming requires invasive code changes, and the databases limit expressiveness by disallowing recursive aggregation. In this paper, we present IceDust, a data modeling language for expressing derived attribute values without committing to a calculation strategy. IceDust provides three strategies for calculating derived values in persistent object graphs: Calculate-on-Read, Calculate-on-Write, and Calculate-Eventually. We have developed a path-based abstract interpretation that provides static dependency analysis to generate code for these strategies. Benchmarks show that different strategies perform better in different scenarios. In addition we have conducted a case study that suggests that derived value calculations of systems used in practice can be expressed in IceDust.

most of tu delft pl group

An incomplete group photo of the SLDE research group at TU Delft. From left to right:

  • Hendrik van Antwerpen
  • Guido Wachsmuth
  • Martijn Dwars
  • Jeff Smits
  • Gabriël Konat
  • Casper Bach Poulsen
  • Vlad Vergu
  • Eduardo Amorim
  • Daco Harkes

Missing are

  • Elmer van Chastelet
  • Danny Groenewegen
  • Jeffrey Goderie
  • Voker Lanting
  • Daniël Pelsmaeker
  • Joey Ezechiëls

and the photographer

  • Eelco Visser