‹Programming› 2019
Mon 1 - Thu 4 April 2019 Genoa, Italy
Wed 3 Apr 2019 12:00 - 12:30 at Paganini - Modularity and Modeling Chair(s): Walter Cazzola

Context. Embedded Domain-Specific Languages (EDSLs) are a common and widely used approach to DSLs in various languages, including Haskell and Scala. There are two main implementation techniques for EDSLs: shallow embeddings and deep embeddings.

Inquiry. Shallow embeddings are quite simple, but they have been criticized in the past for being quite limited in terms of modularity and reuse. In particular, it is often argued that supporting multiple DSL interpretations in shallow embeddings is difficult.

Approach. This paper argues that shallow EDSLs and Object-Oriented Programming (OOP) are closely related. Gibbons and Wu already discussed the relationship between shallow EDSLs and procedural abstraction, while Cook discussed the connection between procedural abstraction and OOP. We make the transitive step in this paper by connecting shallow EDSLs directly to OOP via procedural abstraction. The knowledge about this relationship enables us to improve on implementation techniques for EDSLs.

Knowledge. This paper argues that common OOP mechanisms (including inheritance, subtyping, and type-refinement) increase the modularity and reuse of shallow EDSLs when compared to classical procedural abstraction by enabling a simple way to express multiple, possibly dependent, interpretations.

Grounding. We make our arguments by using Gibbons and Wu’s examples, where procedural abstraction is used in Haskell to model a simple shallow EDSL. We recode that EDSL in Scala and with an improved OO-inspired Haskell encoding. We further illustrate our approach with a case study on refactoring a deep external SQL query processor to make it more modular, shallow, and embedded.

Importance. This work is important for two reasons. Firstly, from an intellectual point of view, this work establishes the connection between shallow embeddings and OOP, which enables a better understanding of both concepts. Secondly, this work illustrates programming techniques that can be used to improve the modularity and reuse of shallow EDSLs.

Wed 3 Apr

11:00 - 12:30: Research Papers - Modularity and Modeling at Paganini
Chair(s): Walter Cazzola Università degli Studi di Milano
programming-2019-papers11:00 - 11:30
Hrshikesh AroraVictoria University of Wellington, New Zealand, Marco ServettoVictoria University Wellington, New Zealand, Bruno C. d. S. OliveiraThe University of Hong Kong, Hong Kong
Link to publication DOI Pre-print
programming-2019-papers11:30 - 12:00
Paulius JuodisiusIT University of Copenhagen, Denmark, Atrisha SarkarUniversity of Waterloo, Canada, Raghava Rao MukkamalaDepartment of Technology, Kristiania University College, Norway, Michal AntkiewiczUniversity of Waterloo, Canada, Krzysztof CzarneckiUniversity of Waterloo, Canada, Andrzej WąsowskiIT University of Copenhagen, Denmark
Link to publication DOI Pre-print
programming-2019-papers12:00 - 12:30
Weixin ZhangThe University of Hong Kong, Hong Kong, Bruno C. d. S. OliveiraThe University of Hong Kong, Hong Kong
Link to publication DOI Pre-print