André L. M. Santos

A transformation-based optimiser for Haskell

Abstract Many compilers do some of their work by means of correctness-preserving, and hopefully performance-improving, program transformations. The Glasgow Haskell Compiler (GHC) takes this idea of “compilation by transformation” as its war-cry, trying to express as much as possible of the compilation process in the form of program transformations. This paper reports on our practical experience of the transformational approach to compilation, in the context of a substantial compiler.

Six years of systematic literature reviews in software engineering: An updated tertiary study

Context: Since the introduction of evidence-based software engineering in 2004, systematic literature review (SLR) has been increasingly used as a method for conducting secondary studies in software engineering. Two tertiary studies, published in 2009 and 2010, identified and analysed 54 SLRs published in journals and conferences in the period between 1st January 2004 and 30th June 2008. Objective: In this article, our goal was to extend and update the two previous tertiary studies to cover the period between 1st July 2008 and 31st December 2009. We analysed the quality, coverage of software engineering topics, and potential impact of published SLRs for education and practice. Method: We performed automatic and manual searches for SLRs published in journals and conference proceedings, analysed the relevant studies, and compared and integrated our findings with the two previous tertiary studies. Results: We found 67 new SLRs addressing 24 software engineering topics. Among these studies, 15 were considered relevant to the undergraduate educational curriculum, and 40 appeared of possible interest to practitioners. We found that the number of SLRs in software engineering is increasing, the overall quality of the studies is improving, and the number of researchers and research organisations worldwide that are conducting SLRs is also increasing and spreading. Conclusion: Our findings suggest that the software engineering research community is starting to adopt SLRs consistently as a research method. However, the majority of the SLRs did not evaluate the quality of primary studies and fail to provide guidelines for practitioners, thus decreasing their potential impact on software engineering practice.

Tracking technical debt — An exploratory case study

The technical debt metaphor is increasingly being used to describe the effect of delaying certain software maintenance tasks on software projects. Practitioners understand intuitively how technical debt can turn into a serious problem if it is left unattended. However, it remains unknown how serious the problem is and whether explicit measurement and management of technical debt is useful. In this paper, we explore the effect of technical debt by tracking a single delayed maintenance task in a real software project throughout its lifecycle and simulate how explicit technical debt management might have changed project outcomes. The results from this study demonstrate how and to what extent technical debt affects software projects. The study also sheds light on the research methodologies that can be used to investigate the technical debt management problem.

Compilation by Transformation in the Glasgow Haskell Compiler

In this paper we describe the full set of local program transformations implemented in the Glasgow Haskell Compiler. The transformations are presented as source to source transformations in a simple functional language. The idea is that by composing these simple and small high level transformations one can achieve most of the benefits of more complicated and specialised transformations, many of which are often implemented as code generation optimisations.

A critical appraisal of systematic reviews in software engineering from the perspective of the research questions asked in the reviews

After a seminal article introducing-evidence based software engineering in 2004, systematic reviews (SR) have been increasingly used as a method for conducting secondary studies in software engineering. Our goal is to critically appraise the use of SR in software engineering with respect to the research questions asked and the ways the questions were used in the reviews. We analyzed 53 literature reviews that had been collected in two published tertiary studies. We found that over 65% of the research questions asked in the reviews were exploratory and only 15% investigated causality questions. We concluded that there is a need for a consistent use of terminology to classify secondary studies and that reports of literature reviews should follow reporting guidelines to support assessment and comparison.

Streamlining domain analysis for digital games product lines

Digital games and their development process are quite peculiar when compared to other software in general. However, current domain engineering processes do not addresses such peculiarities and, not surprisingly, successful cases of software product lines (SPLs) for digital games cannot be found in the literature nor the industry. With such a motivation, this paper focuses on streamlining and enriching the Domain Analysis process for SPLs targeted at digital games. Guidelines are provided for making Domain Analysis tasks aware of digital games peculiarities, in order to tackle the challenges of and benefit from the unique characteristics of such a macro-domain. A case study for an SPL aimed at arcade-based games is also presented to illustrate and evaluate the proposed guidelines.

Computer games software factory and edutainment platform for microsoft .NET

Abstract: An environment targeted at computer games development industrialisation in the .NET platform is presented. A computer game product line definition and its architecture are specified and implemented by means of software factory assets, such as a visual designer based on a domain- specific language, semantic validators and code generators. The proposed approach is then illustrated and empirically validated by the creation of real world case studies. Finally, it is investigated how the proposed factory can be used as an edutainment platform for Computer Science 1 and 2 courses. The final intention is to empower game developers and designers to work more productively, with a higher level of abstraction and closer to their application domain.

Morphological Plasticity in the Reef Zoanthid Palythoa caribaeorum as an Adaptive Strategy

We compared morphology of Palythoa caribaeorum (number of polyps, area, diameter and height) occupying three sites located at different distances from a harbor area and with different environmental conditions, such as sedimentation. Seasonality was also considered by comparing morphology during the wet and dry seasons. GLM analyses showed significant main and first-order interaction effects between sites and seasons for each of the four morphological variables measured. Only at the site directly in front of the harbor area there was no seasonal variation. At the other two sites, no significant differences were found when the average pairwise distance of each morphological character was compared between seasons for each site. This indicates that these characters vary in a similar way and suggests growth conditions intrinsic to the species. Environmental homogeneity at the harbor area seems to promote homogeneous morphometry, which indicates different biological strategies and suggests that this species adapts to distinct environments.

Applying Metrics to Identify and Monitor Technical Debt Items during Software Evolution

The Technical Debt (TD) metaphor has been used in the software community as a way to manage and communicate the long-term consequences that some technical decisions may cause. Although intuitive, researches in TD do not discuss practical approaches to identify and monitor TD items, which could be applied in a transparent way during the process of software evolution. This work proposes a technique based on software metrics that automates the process of TD identification and monitoring. For that end, a subset of metrics was analyzed and related to aspects of TD items. As a form to validate the technique, it was used to analyze a TD item from a past 7 years multinational project. Evidences suggest that TD items can be related to software metrics so that software metric tools could be an important resource to automate the identification and monitoring of TD items.

The software perspective for energy-efficient mobile applications development

Nowadays, there is a growing concern about the energy consumption of the ICT industry. This fact has given rise to a lot of energy saving research activities, which mainly focus on the hardware side of computational systems. However, it is tempting to suppose that only hardware dissipates power, not software. This paper discusses several software methods, which could be explored to develop energy-efficient mobile techniques. We argue that the development of applications that consider the energy saving, as one of their requirements, can result in a significant final energy saving because solutions will be part of the own software and they do not depend of external resources to obtain a lower consumption.