Search Results

Documents authored by Ferreira, João F.

Document
DOI: 10.4230/LIPIcs.ECOOP.2025.11
Contract Usage and Evolution in Android Mobile Applications

Authors: David R. Ferreira, Alexandra Mendes, João F. Ferreira, and Carolina Carreira

Published in: LIPIcs, Volume 333, 39th European Conference on Object-Oriented Programming (ECOOP 2025)

Abstract
Contracts and assertions are effective methods to enhance software quality by enforcing preconditions, postconditions, and invariants. Previous research has demonstrated the value of contracts in traditional software development. However, the adoption and impact of contracts in the context of mobile app development, particularly of Android apps, remain unexplored. To address this, we present the first large-scale empirical study on the use of contracts in Android apps, written in Java or Kotlin. We consider contract elements divided into five categories: conditional runtime exceptions, APIs, annotations, assertions, and other. We analyzed 2,390 Android apps from the F-Droid repository and processed 52,977 KLOC to determine 1) how and to what extent contracts are used, 2) which language features are used to denote contracts, 3) how contract usage evolves from the first to the last version, and 4) whether contracts are used safely in the context of program evolution and inheritance. Our findings include: 1) although most apps do not specify contracts, annotation-based approaches are the most popular; 2) apps that use contracts continue to use them in later versions, but the number of methods increases at a higher rate than the number of contracts; and 3) there are potentially unsafe specification changes when apps evolve and in subtyping relationships, which indicates a lack of specification stability. Finally, we present a qualitative study that gathers challenges faced by practitioners when using contracts and that validates our recommendations.
Cite as

David R. Ferreira, Alexandra Mendes, João F. Ferreira, and Carolina Carreira. Contract Usage and Evolution in Android Mobile Applications. In 39th European Conference on Object-Oriented Programming (ECOOP 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 333, pp. 11:1-11:30, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2025)

Copy BibTex To Clipboard

@InProceedings{ferreira_et_al:LIPIcs.ECOOP.2025.11,
  author =	{Ferreira, David R. and Mendes, Alexandra and Ferreira, Jo\~{a}o F. and Carreira, Carolina},
  title =	{{Contract Usage and Evolution in Android Mobile Applications}},
  booktitle =	{39th European Conference on Object-Oriented Programming (ECOOP 2025)},
  pages =	{11:1--11:30},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-373-7},
  ISSN =	{1868-8969},
  year =	{2025},
  volume =	{333},
  editor =	{Aldrich, Jonathan and Silva, Alexandra},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECOOP.2025.11},
  URN =		{urn:nbn:de:0030-drops-233041},
  doi =		{10.4230/LIPIcs.ECOOP.2025.11},
  annote =	{Keywords: Contracts, Design by Contract, DbC, Android, Java, Kotlin}
}
Document
DOI: 10.4230/LIPIcs.ECOOP.2023.4
Hoogle⋆: Constants and λ-abstractions in Petri-net-based Synthesis using Symbolic Execution

Authors: Henrique Botelho Guerra, João F. Ferreira, and João Costa Seco

Published in: LIPIcs, Volume 263, 37th European Conference on Object-Oriented Programming (ECOOP 2023)

Abstract
Type-directed component-based program synthesis is the task of automatically building a function with applications of available components and whose type matches a given goal type. Existing approaches to component-based synthesis, based on classical proof search, cannot deal with large sets of components. Recently, Hoogle+, a component-based synthesizer for Haskell, overcomes this issue by reducing the search problem to a Petri-net reachability problem. However, Hoogle+ cannot synthesize constants nor λ-abstractions, which limits the problems that it can solve. We present Hoogle⋆, an extension to Hoogle+ that brings constants and λ-abstractions to the search space, in two independent steps. First, we introduce the notion of wildcard component, a component that matches all types. This enables the algorithm to produce incomplete functions, i.e., functions containing occurrences of the wildcard component. Second, we complete those functions, by replacing each occurrence with constants or custom-defined λ-abstractions. We have chosen to find constants by means of an inference algorithm: we present a new unification algorithm based on symbolic execution that uses the input-output examples supplied by the user to compute substitutions for the occurrences of the wildcard. When compared to Hoogle+, Hoogle⋆ can solve more kinds of problems, especially problems that require the generation of constants and λ-abstractions, without performance degradation.
Cite as

Henrique Botelho Guerra, João F. Ferreira, and João Costa Seco. Hoogle⋆: Constants and λ-abstractions in Petri-net-based Synthesis using Symbolic Execution. In 37th European Conference on Object-Oriented Programming (ECOOP 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 263, pp. 4:1-4:28, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)

Copy BibTex To Clipboard

@InProceedings{botelhoguerra_et_al:LIPIcs.ECOOP.2023.4,
  author =	{Botelho Guerra, Henrique and Ferreira, Jo\~{a}o F. and Costa Seco, Jo\~{a}o},
  title =	{{Hoogle⋆: Constants and \lambda-abstractions in Petri-net-based Synthesis using Symbolic Execution}},
  booktitle =	{37th European Conference on Object-Oriented Programming (ECOOP 2023)},
  pages =	{4:1--4:28},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-281-5},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{263},
  editor =	{Ali, Karim and Salvaneschi, Guido},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECOOP.2023.4},
  URN =		{urn:nbn:de:0030-drops-181974},
  doi =		{10.4230/LIPIcs.ECOOP.2023.4},
  annote =	{Keywords: Type-directed, component-based, program synthesis, symbolic execution, unification, Haskell}
}
Document
Artifact
DOI: 10.4230/DARTS.9.2.20
Hoogle⋆: Constants and λ-abstractions in Petri-net-based Synthesis using Symbolic Execution (Artifact)

Authors: Henrique Botelho Guerra, João F. Ferreira, and João Costa Seco

Published in: DARTS, Volume 9, Issue 2, Special Issue of the 37th European Conference on Object-Oriented Programming (ECOOP 2023)

Abstract
Type-directed component-based program synthesis is the task of automatically building a function with applications of available components and whose type matches a given goal type. Existing approaches to component-based synthesis, based on classical proof search, cannot deal with large sets of components. Recently, Hoogle+, a component-based synthesizer for Haskell, overcomes this issue by reducing the search problem to a Petri-net reachability problem. However, Hoogle+ cannot synthesize constants nor λ-abstractions, which limits the problems that it can solve. We present Hoogle⋆, an extension to Hoogle+ that brings constants and λ-abstractions to the search space, in two independent steps. First, we introduce the notion of wildcard component, a component that matches all types. This enables the algorithm to produce incomplete functions, i.e., functions containing occurrences of the wildcard component. Second, we complete those functions, by replacing each occurrence with constants or custom-defined λ-abstractions. We have chosen to find constants by means of an inference algorithm: we present a new unification algorithm based on symbolic execution that uses the input-output examples supplied by the user to compute substitutions for the occurrences of the wildcard. When compared to Hoogle+, Hoogle⋆ can solve more kinds of problems, especially problems that require the generation of constants and λ-abstractions, without performance degradation. The artifact contains the source code of Hoogle⋆, as well as scripts to reproduce the evaluation done in the paper.
Cite as

Henrique Botelho Guerra, João F. Ferreira, and João Costa Seco. Hoogle⋆: Constants and λ-abstractions in Petri-net-based Synthesis using Symbolic Execution (Artifact). In Special Issue of the 37th European Conference on Object-Oriented Programming (ECOOP 2023). Dagstuhl Artifacts Series (DARTS), Volume 9, Issue 2, pp. 20:1-20:3, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)

Copy BibTex To Clipboard

@Article{botelhoguerra_et_al:DARTS.9.2.20,
  author =	{Botelho Guerra, Henrique and Ferreira, Jo\~{a}o F. and Costa Seco, Jo\~{a}o},
  title =	{{Hoogle⋆: Constants and \lambda-abstractions in Petri-net-based Synthesis using Symbolic Execution (Artifact)}},
  pages =	{20:1--20:3},
  journal =	{Dagstuhl Artifacts Series},
  ISSN =	{2509-8195},
  year =	{2023},
  volume =	{9},
  number =	{2},
  editor =	{Botelho Guerra, Henrique and Ferreira, Jo\~{a}o F. and Costa Seco, Jo\~{a}o},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DARTS.9.2.20},
  URN =		{urn:nbn:de:0030-drops-182609},
  doi =		{10.4230/DARTS.9.2.20},
  annote =	{Keywords: Type-directed, component-based, program synthesis, symbolic execution, unification, Haskell}
}
Questions / Remarks / Feedback
X

Feedback for Dagstuhl Publishing


Thanks for your feedback!

Feedback submitted

Could not send message

Please try again later or send an E-mail
© 2023-2025 Schloss Dagstuhl – LZI GmbH About DROPS Imprint Privacy Contact