Parsing visual languages with picture layout grammars

The term “visual language” means different things to different people. To some, it means the objects handled by the language are visual. To others, it means the language itself is visual. To the first group of people, “visual language” means “language for processing visual information,” or “visual information processing language.” To the second group of people, “visual language” means “language for programming with visual expressions,” or “visual programming language.”

This paper presents a new programming language named SPARCL that has four major elements: it is a visual language, it is a logic programming language, it relies on sets to organize data, and it supports partitioning constraints on the contents of sets. It is a visual programming language in that the representation of the language depends extensively on non-textual graphics and the programming process relies on graphical manipulation of this representation. It is a logic programming language in that the underlying semantics of the language is the resolution of clauses of a Horn-like subset of first order predicate logic. It uses sets as the only method of combining terms to build complex terms. Finally, one may constrain a set's structure by specifying a partitioning into pairwise disjoint subsets.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Visual programming language research has evolved greatly since its early days. At first, attempts at visual programming mostly took the form of flowchart-like diagrams. But in recent years, a wide number of innovative approaches have been incorporated into visual languages, including object-oriented programming, form-based programming, programming by demonstration, and dataflow programming. Unfortunately, while many of these systems represent important ideas, only a few have been successful as complete visual programming languages. This tutorial explains why this is true, and describes ways in which the problem can be addressed. This tutorial explores the issues behind the successes and failures of earlier approaches from a design perspective. It identifies characteristics of successful visual programming languages, and explains how to design an object-oriented language that maintains those characteristics. It shows solutions to a number of problems by looking at existing visual programming languages, including Prograph.

: A general purpose visual programming language, based on object-oriented methodology, offers substantial Benefits of reusable code, shorter creation and maintenance time, faster overall understanding of the code, and reduced staff learning time. It should be an ideal fit for sites with long-lived code or very large bodies of code. The value of visual programming languages is well understood for very specific tasks; this report reviews the plan for research and design of a general purpose visual object-oriented programming language through nine steps, which includes general specifications for the preferred language and environment.

Digital nations have become dependent on computer applications. One of the most important part of literacy in today’s digital and connected word are the basics of computer applications development and usage, but also algorithmic thinking. Programmers, developers, analysts are very wanted resource in business, administration and educational organizations. Job portals contain a lot of well-paid job offers for developers, data scientists, knowledge engineers or robotic process automation developers. Still more and more specialists in these areas are needed not only by IT market but also other sectors of the economy. Therefore, schools and universities introduce many courses concerning process modeling, developing, programming and customizing applications used in management, finance, logistics or engineering. Programming seems to be quite difficult to learn, therefore several educational programming environments and the new easier languages like visual programming languages were developed, so that more people, not necessarily specialists, could create new IT tools and speed up development of the information society.The aim of the article is to present the role of visual programming languages like Scratch in encouraging university students to create algorithms and start programming. The paper presents the characteristic of Scratch visual programming language, the framework of VBA programming course with elements of Scratch. It contains also students’ opinions about learning the basics of programming with visual programming language. In the main part of the article the author presents the results of the survey that was at conducted at the beginning of 2019 on a group of Polish Master’s students (n=119) The author’s observation and students’ opinions allow to conclude that Scratch is very easy to access and to use. It makes introduction to programming more enjoyable, helps to concentrate on the problem, solution structure, and the flow of the process. Scratch platform is not an ideal tool, however it allows for faster introduction of new elements of programming languages such as variables, loops, code blocks, objects. Finally, visual programming languages thanks to its easiness and quickly visible final effect (working application) encourages students to self-development in the field of computer programming. Performed research indicates also that business students notice the benefits of knowing basics of programing, they would like to attend basic programing classes. Students acquire knowledge and skills mainly performing instructions received from the teacher (86%) and watching video tutorials. The comparative analysis showed also some differences between various groups of students. Therefore, tools like Scratch can be successfully used to develop IT courses for non-majors. Many advantages make Scratch useful in introductory programming courses prepared for business students that frequently had no prior experience in the area of IT applications development.

CombiLog is a logic programming language that uses a small set of basic operators to build larger structures. Although the programs are built strictly through composition, the resulting code is often difficult to read and understand. Empirical studies on program creation both with visual programming language and traditional programming indicate that visual approaches may outperform traditional approaches to programming. Thus, CombiLog could gain largely from a visual interface to support the development process. With a visual interface the resulting system can be regarded as a declarative visual logic programming language, ViColl.

Many people argue that Visual Programming languages are self-documenting. This article points out that there is no such thing as a self-documenting language. Besides this, many popular methods used to document programs written in other languages do not suit Visual Languages perfectly, and need some tailoring. Therefore, the authors propose a visual adaptation of the dataflow method of documentation. They also present versions of instantiated documentation and denotational semantics applied to visual languages. Finally, they present a Prolog based complete example of documentation.

Managing the graphical complexity of real-life programs expressed in visual programming languages is a great challenge in each visual programming environment. Besides general methods like displaying/layouting graphs and icons on different levels of abstraction or organizing multiple window environments, built-in language mechanisms which permit the structured and modular design of visual programs are essential to overcome this problem. We address these problems by discussing a concept for visual modules in a diagrammatic parallel language as well as a method to describe massive parallel programs consisting of hundreds of processes by means of a visual replication mechanism. >

Improving students' understanding of basic programming concepts through visual programming language: The role of self-efficacy

A class of visual programming languages whose members share a common group of underlying principles is identified. In this class (the demand-driven temporal-assignment visual language model), the elimination of certain duplicate computations is a natural by-product of the model. The potential time and space complexity characteristics for visual languages based on this model are discussed, and a method that makes use of these characteristics is presented. >

Representation Design Benchmarks: A Design-Time Aid for VPL Navigable Static Representations

The Programming Languages (PL) Track provides researchers and practitioners with a forum to present their ideas and experience in designing new programming concepts and implementing programming languages. It includes the topics of Compiling Techniques, Domain-Specific Languages, Formal Semantics and Syntax, Garbage Collection, Language Design and Implementation, Languages for Modeling, Model-Driven Development and Model Transformation, New Programming Language Ideas and Concepts, New Programming Paradigms, Practical Experiences with Programming Languages, Program Analysis and Verification, Program Generation and Transformation, Programming Languages from All Paradigms (Agent-Oriented, Aspect-Oriented, Functional, Logic, Object-Oriented, etc.), and Visual Programming Languages.

It is well documented, and has been the topic of much research, that Computer Science courses tend to have higher than average drop out rates at third level. This is a problem that needs to be addressed with urgency but also caution. The required number of Computer Science graduates is growing every year but the number of graduates is not meeting this demand and one way that this problem can be alleviated is to encourage students at an early age towards studying Computer Science courses. This paper presents a systematic literature review on the role of visual and textual programming languages when learning to program, particularly as a first programming language. The approach is systematic, in that a structured search of electronic resources has been conducted, and the results are presented and quantitatively analysed. This study will give insight into whether or not the current approaches to teaching young learners programming are viable, and examines what we can do to increase the interest and retention of these students as they progress through their education.

Prograph is a programming environment and language which has been available on the Apple Macintosh platform for more than 5 years. It provides a sophisticated application builder, together with a visual programming language, supported by a powerful program development environment. The programming language uses an object-oriented model for data abstraction and the logic is based on a dataflow model of computation, specified graphically.Graphical dataflow gives programmers a clear view of the potential for exploitation of concurrency and so the Prograph language appears to give some leverage for the programming of parallel or distributed systems. This still leaves many issues unresolved, however, since for example dataflow is usually associated with fine-grain parallelism, but expected target architectures are unlikely to support fine-grain parallelism efficiently. This paper discusses the preliminary investigation of the issues of Prograph and parallelism.KeywordsParallel EvaluationApple MacintoshDataflow GraphDataflow ModelRemote ExecutionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Rapid prototyping of domain-specific software requires a systematic software development methodology and user-friendly tools [20]. As visual tools are becoming increasingly popular for non-computing professionals and end-users, visual programming languages (VPLs) would potentially challenge traditional specification languages for rapid software prototyping due to their intuitiveness and ease-of-use. Different from CASE toolsets, VPLs are executable specification languages that are defined by graph grammars and syntax-directed rewriting rules, apart from being at a high level. This means that the prototyped domain software can also be rigorously verified to ensure that it is safe and risk-free. We call VPLs designed for specific application domains as Domain-Specific Visual Languages (DSVLs).