Automatic Repair of Infinite Loops

Research on automatic software repair is concerned with the development of systems that automatically detect and repair bugs. One well-known class of bugs is the infinite loop. Every computer programmer or user has, at least once, experienced this type of bug. We state the problem of repairing infinite loops in the context of test-suite based software repair: given a test suite with at least one failing test, generate a patch that makes all test cases pass. Consequently, repairing infinites loop means having at least one test case that hangs by triggering the infinite loop. Our system to automatically repair infinite loops is called $Infinitel$. We develop a technique to manipulate loops so that one can dynamically analyze the number of iterations of loops; decide to interrupt the loop execution; and dynamically examine the state of the loop on a per-iteration basis. Then, in order to synthesize a new loop condition, we encode this set of program states as a code synthesis problem using a technique based on Satisfiability Modulo Theory (SMT). We evaluate our technique on seven seeded-bugs and on seven real-bugs. $Infinitel$ is able to repair all of them, within seconds up to one hour on a standard laptop configuration

TeXTracT: a Web-based Tool for Building NLP-enabled Applications

Over the last few years, the software industry has showed an increasing interest for applications with Natural Language Processing (NLP) capabilities. Several cloud-based solutions have emerged with the purpose of simplifying and streamlining the integration of NLP techniques via Web services. These NLP techniques cover tasks such as language detection, entity recognition, sentiment analysis, classification, among others. However, the services provided are not always as extensible and configurable as a developer may want, preventing their use in industry-grade developments and limiting their adoption in specialized domains (e.g., for analyzing technical documentation). In this context, we have developed a tool called TeXTracT that is designed to be composable, extensible, configurable and accessible. In our tool, NLP techniques can be accessed independently and orchestrated in a pipeline via RESTful Web services. Moreover, the architecture supports the setup and deployment of NLP techniques on demand. The NLP infrastructure is built upon the UIMA framework, which defines communication protocols and uniform service interfaces for text analysis modules. TeXTracT has been evaluated in two case-studies to assess its pros and cons.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Deploying and sharing U-Compare workflows as web services

BACKGROUND: U-Compare is a text mining platform that allows the construction, evaluation and comparison of text mining workflows. U-Compare contains a large library of components that are tuned to the biomedical domain. Users can rapidly develop biomedical text mining workflows by mixing and matching U-Compare’s components. Workflows developed using U-Compare can be exported and sent to other users who, in turn, can import and re-use them. However, the resulting workflows are standalone applications, i.e., software tools that run and are accessible only via a local machine, and that can only be run with the U-Compare platform. RESULTS: We address the above issues by extending U-Compare to convert standalone workflows into web services automatically, via a two-click process. The resulting web services can be registered on a central server and made publicly available. Alternatively, users can make web services available on their own servers, after installing the web application framework, which is part of the extension to U-Compare. We have performed a user-oriented evaluation of the proposed extension, by asking users who have tested the enhanced functionality of U-Compare to complete questionnaires that assess its functionality, reliability, usability, efficiency and maintainability. The results obtained reveal that the new functionality is well received by users. CONCLUSIONS: The web services produced by U-Compare are built on top of open standards, i.e., REST and SOAP protocols, and therefore, they are decoupled from the underlying platform. Exported workflows can be integrated with any application that supports these open standards. We demonstrate how the newly extended U-Compare enhances the cross-platform interoperability of workflows, by seamlessly importing a number of text mining workflow web services exported from U-Compare into Taverna, i.e., a generic scientific workflow construction platform