Cross-Language Interoperability in a Multi-Language Runtime

A framework for compiler construction of functional programming languages is described. The framework has been designed to allow experimenting with functional programming languages and their implementations. Its three main characteristics are: (1) given the existing implementation of a functional programming language (not necessary in a source code), the implementation of a new functional programming language can be easily and efficiently developed, using the framework; (2) the framework enables enhancement of already implemented languages with new features; and (3) implementations of the languages in the framework are transparent, which can be freely exchanged between the languages.

Many of today’s programming languages are broken. Poor performance, lack of features and hard-to-reason-about semantics can cost dearly in software maintenance and inecient execution. The problem is only getting worse with programming languages proliferating and hardware becoming more complicated. An important reason for this brokenness is that much of language design is implementation-driven. The diculties in implementation and insucient understanding of concepts bake bad designs into the language itself. Concurrency, architectural details and garbage collection are three fundamental concerns that contribute much to the complexities of implementing managed languages. We propose the micro virtual machine, a thin abstraction designed specifically to relieve implementers of managed languages of the most fundamental implementation challenges that currently impede good design. The micro virtual machine targets abstractions over memory (garbage collection), architecture (compiler backend), and concurrency. We motivate the micro virtual machine and give an account of the design and initial experience of a concrete instance, which we call Mu, built over a two year period. Our goal is to remove an important barrier to performant and semantically sound managed language design and implementation.

Object oriented (OO) is the most accepted object modeling languages nowadays. Although OO languages are successful in modeling real world entities, nevertheless, there is little to no support for modeling state of object precisely in code. To overcome this problem, a new general purpose programming language is proposed that is built on two paradigms which are typestate-oriented and permission-based. One of the most vital factor for every language to be accepted and effective for users is having an enhanced standard library and clearly one of the most important parts is Input and Output (I/O) Application Programming Interface (API). One of a new programming language is Plaid language. Since the Plaid is at its early stage of development, I/O features provided by the Plaid standard library are very basic and limited. This paper presents I/O API that we have developed for the Plaid based on the features provided by Java I/O API. For the evaluation we used two metrics which are the number of features provided by I/O API, and the number of exceptions eliminated by using Plaid and typestate-oriented programming language.

Modular language implementation in Rascal – experience report

The increasing attention in science education reform documents to language and literacy, coupled with the growing linguistic diversity of United States classrooms, means that science teacher educators and researchers are facing an important task of preparing secondary science preservice teachers (PSTs) to teach a language‐ and literacy‐integrated form of science in linguistically diverse classrooms. Unfortunately, research in this field is in its nascency, and while some studies have addressed PSTs' instructional planning for and implementation of language‐ and literacy‐integrated science instruction, none have considered the unique contextual factors that inform PSTs' uptake of these reform‐oriented instructional practices, despite many studies suggesting student‐teaching contexts are a key factor in PSTs' instructional decisions. The purpose of this multiple case study was to consider the unique contextual factors that supported and constrained three PSTs' uptake of language‐ and literacy‐integrated science practices through a Cultural‐Historical Activity Theory (CHAT) lens. Findings indicated that PSTs' implementation of language‐ and literacy‐integrated science instruction was shaped by interactions among the mediating elements of their student teaching activity systems, including PSTs' division of labor with mentor teachers, the classroom and school norms, PSTs' perceptions of their classroom communities, and PSTs' past life experiences and resources. These findings highlight the roles that different elements of learning‐to‐teach contexts can play in PSTs' enactment of reform‐oriented instruction. Implications for science teacher education, instruction for emergent bilinguals, and research are discussed.

Awale game is one of the famous board games from Africa with many variants and is now played worldwide in various forms. In this paper, we propose an open-source Application Programming Interface (API) for developers to allow an easy implementation of the various variants of Awale as well as artificial intelligence based players. The API is available online at https://github.com/Machine-Intelligence-For-You/Awale. Based on this API, we propose a PC Awale game, a mobile Awale game, and an Augmented Reality Game. The Awale API, PC game, and mobile game are implemented in the programming language Java while the game in Augmented Reality is realized with the C# programming language, Unity 3D game engine and the Vuforia Augmented Reality SDK. The various tests carried out show that the API and the different games are totally functional. This API was also used for the first edition of MAIC, an Artificial Intelligence contest https://mify-ai.com/maic2017/.

Application Programming Interfaces (APIs) are everyday tools for every software professional. When creating an API, a designer typically abstracts the tasks the API intends to perform. The API user, on the other hand, should use the API to perform specific-propose tasks. During the development of an API, the designer needs to write dialogues with which the user will interact with the API, performing a conversation between them. In this way, an API capable of offering effective dialogues to its users is called a conversational API. A conversational API is the one that is capable of communicating to its users its form of use and its internal logic of operation, making it clear the design decisions when abstracting concepts and tasks. In this paper, we present Colloquy, an evidence-based method to support the design of conversational APIs. Colloquy was conceived based on the lessons learned from an action research we conducted to identify effective strategies for designing conversational APIs. For six months, we followed the redesign of an existing API developed at an R&D laboratory of a large IT company. In this paper, we also present the first empirical evaluation of Colloquy. We conducted a case study in which the method was employed to design an API for refactoring source code in the Java programming language. Among other benefits, we found that Colloquy was effective in developing empathy with users and modeling conversations with them. Besides, Colloquy contributed to identifying new requirements and created models as API documentation.

In modern software engineering, API (Application Programming Interface) is widely used to develop applications rapidly by reusing data structure, frameworks, class libs, and etc. However, due to the considerable number of interfaces, lack of documents and timely maintenance and updates, APIs are often used in a wrong way. Therefore, it has become an important problem to detect API misuse in an automatic way. Many existing automatic API detecting methods do not make full use of APIs’ potential semantic information and independent integrity of each API. In this paper, we employ Stacked LSTM to learn the API usage specification to detect the API misuse defects. Specifically, first, we obtain ACSG (API Call Syntax Graph) through the static analysis of source code. And then, based on ACSG, we generate API sequences, and transform the sequences into for training. Third, in order to represent the APIs in a semantic way, we apply word2vec as a pre-training model to embed features of each API. Though the stacked LSTM model, we regard embedding precious API sequence as the input to model the API use specifications and discover the potential API misuse defects by judging whether the next API is in the output (API probability list) or not. We design experiments to evaluate the effectiveness our method with Java Cryptography APIs and their used code, and the results show the advancement of our proposed method.

Virtual machines raise the abstraction level of the execution environment at the cost of restricting the set of supported languages. Moreover, the ability of a language implementation to integrate with other languages hosted on the same virtual machine typically constrains the features of the language. In this paper, we present a highly flexible yet efficient approach to hosting multiple programming languages on an objectoriented virtual machine. Our approach is based on extending the interface of each class with language-specific wrapper methods, offering each language a tailored view of a given class. This approach can be deployed both on a statically typed virtual machine, such as the JVM, and on a dynamic virtual machine, such as a Smalltalk virtual machine. We have implemented our approach to language interoperability on top of a prototype virtual machine for embedded systems based on the Smalltalk object model, which provides interoperability for embedded versions of the Smalltalk, Java, and BETA programming languages. (Less)

This volume contains the proceedings of the Sixth Workshop on the Implementation, Compilation, Optimization of Object-Oriented Languages, Programs and Systems (ICOOOLPS). Computer programming languages, especially Object-Oriented languages, are pervasive and play a significant role in computer science and engineering life and sometime appear as ubiquitous and completely mature. However, despite a large number of works, there still is a clear need for solutions for efficient implementation and compilation of OO languages in various application domains ranging from embedded and real-time systems to desktop systems. The ICOOOLPS workshop thus aims to address this crucial issue of optimization, mainly but not only in OO languages, programs and systems. It intends to do so by bringing together researchers and practitioners working in the field of implementation and optimization of programming languages. Its main goals are identifying fundamental bases and key current issues pertaining to the efficient implementation, compilation and optimization of OO languages, and outlining future challenges and research directions.

Code examples are important resources for expressing correct application programming interface (API) usages. However, many framework and library APIs fail in offering sufficient code examples in corresponding API documentations. This is because constructing proper code examples for documentation purpose takes significant developers' efforts. To reduce such effort, this work proposes a methodology, PropER-Doc, that recommends proper code examples for documentation purpose. PropER-Doc accepts queries from API developers and utilizes code search engines (CSEs) to collect corresponding code example candidates. The structural and conceptual links between API elements are captured from the API implementation and available API documents to guide candidate recommendation. During recommendation, PropER-Doc groups collected candidates based on involved API types for distinguishing different API usages. To assist API developers in selecting proper candidates, a diagrammatic presentation and three code example appropriateness metrics are also developed in {PropER-Doc}. Two case studies on Eclipse JDT framework are conducted to confirm the effectiveness of PropER-Doc.

There are several acoustic monitoring software packages that allow for the creation and execution of algorithms that automate detection, classification, and localization (DCL). Algorithms written for one program are generally not portable to other programs, and usually must be written in a specific programming language. We have developed an application programming interface (API) that seeks to resolve these issues by providing a plugin framework for creating algorithms for two acoustic monitoring packages: Ishmael and PAMGuard. This API will allow new detection, classification, and localization algorithms to be written for these programs without requiring knowledge of the monitoring software’s source code or inner workings, and lets a single implementation run on either platform. The API also allows users to write DCL algorithms in a wide variety of languages. We hope that this will promote the sharing and reuse of algorithm code. [Funding from ONR.]

Safepoints are a virtual machine mechanism that allows one thread to suspend other threads in a known state so that runtime actions can be performed without interruption and with data structures in a consistent state. Many virtual machines use safepoints as a mechanism to provide services such as stop-the-world garbage collection, debugging, and modification to running code such as installing or replacing classes. Languages implemented on these virtual machines may have access to these services, but not directly to the safepoint mechanism itself. We show that safepoints have many useful applications for the implementation of guest languages running on a virtual machine. We describe an API for using safepoints in languages that were implemented under the Truffle language implementation framework on the Java Virtual Machine and show several applications of the API to implement useful guest-language functionality. We present an efficient implementation of this API, when running in combination with the Graal dynamic compiler. We also demonstrate that our safepoints cause zero overhead with respect to peak performance and statistically insignificant overhead with respect to compilation time. We compare this to other techniques that could be used to implement the same functionality and demonstrate the large overhead that they incur.

APIs (application programming interfaces) play a key role in software development. Virtually, all programmers are potential users of third-party APIs. From the perspective of the theory of Semiotic Engineering, we may characterize an API as an artifact mediating the communication between two types of developers: the API designers and its users. During the construction of an API, the designers should establish proper dialogues with the users. These dialogues will enable the conversation of these actors at the interaction time. In this way, we define a conversational API as an API capable of offering effective dialogues to its users. In this paper, we introduce Colloquy, a method for supporting the design of conversational APIs. Colloquy results from the lessons learnt during an action research conducted for redesigning a real and complex API. The set of Colloquy resources allow API designers to go beyond conventional concerns with usability. We also report in this paper a case study in which Colloquy was used for redesigning a refactoring API. The study findings indicate the method helped the designer creating empathy with the API users, as well as better reflecting and depicting the requirements and the conversations that the API should attend to the different user profiles.

One of the modern paradigms to develop an application is object oriented analysis and design. In this paradigm, there are several objects and each object plays some specific roles in applications. In an application, we must distinguish between procedural semantics and declarative semantics for their implementation in a specific programming language. For the procedural semantics, we can write a set of instructions that must be executed sequentially. The declarative semantics declare a set of facts and rules. They do not specify the sequence of steps for doing the processing. In this paper, we present four taxonomies for the rules in object-oriented paradigm and discuss how the paradigm can be extended to support declarative semantic of applications. Then, the rules in the taxonomies are evaluated in four case studies. After that, an approach is recommended for finding and implementation of declarative semantics, based on some practical experience obtained from the evaluation.