Mobile Applications in X-KLAIM

Networking has turned computers from isolated data processors into powerful communication and elaboration devices, called global computers; an illustrative example is the World–Wide Web. Global computers are rapidly evolving towards programmability. The new scenario has called for new programming languages and paradigms centered around the notions of mobility and location awareness. In this paper, we briefly present X-KLAIM, an experimental programming language for global computers, and show a few programming examples

Quantum Programming Made Easy

We present IQu, namely a quantum programming language that extends Reynold's Idealized Algol, the paradigmatic core of Algol-like languages. IQu combines imperative programming with high-order features, mediated by a simple type theory. IQu mildly merges its quantum features with the classical programming style that we can experiment through Idealized Algol, the aim being to ease a transition towards the quantum programming world. The proposed extension is done along two main directions. First, IQu makes the access to quantum co-processors by means of quantum stores. Second, IQu includes some support for the direct manipulation of quantum circuits, in accordance with recent trends in the development of quantum programming languages. Finally, we show that IQu is quite effective in expressing well-known quantum algorithms.Comment: In Proceedings Linearity-TLLA 2018, arXiv:1904.0615

C-Sheep: Controlling Entities in a 3D Virtual World as a Tool for Computer Science Education

One of the challenges in teaching computer science in general and computer programming in particular is to maintain the interest of students, who often perceive the subject as difficult and tedious. To this end, we introduce C-Sheep, a mini-language-like system for computer science education, using a state of the art rendering engine, usually found in entertainment systems. The intention is to motivate students to spend more time programming, which can be achieved by providing an enjoyable experience. Computer programming is an essential skill for software developers and as such is always an integral part of every computer science curriculum. However, even if students are pursuing a computer science related degree, it can be very difficult to interest them in the act of computer programming, the writing of software, itself. In the C-Sheep system this is addressed by using the visual gimmickry of modern computer games, which allows programs to provide instant visualisation of algorithms. This visual feedback is invaluable to the understanding of how the algorithm works, and - if there are unintended results - how errors in the program can be debugged. The C-Sheep programming language is a (100% compatible) subset of the ANSI C programming language. Apart from just being a tool for learning the basics of the C programming language, C-Sheep implements the C control structures that are required for teaching the basic computer science principles encountered in structured programming. Unlike other teaching languages which have minimal syntax and which are variable free to provide an environment with minimal complexity, C-Sheep allows the declaration and use of variables. C-Sheep also supports the definition of sub-routines (functions) which can be called recursively. "The Meadow" virtual environment is the virtual world in which entities (in our case sheep) controlled by C-Sheep programs exist. This micro world provides a graphical representation of the algorithms used in the programs controlling the virtual entities. Their position and orientation within the virtual world visualise the current state of the program. "The Meadow" is based on our proprietary "Crossbow" game engine which incorporates a virtual machine for executing CSheep programs. The Crossbow Engine is a compact game engine which is flexible in design and offers a number of features common to more complex engines. The Crossbow Virtual Machine used with C-Sheep in "The Meadow" - an improvement on the ZBL/0 virtual machine - is a module of the Crossbow Engine. The C-Sheep system also provides a counterpart library for C, mirroring the CSheep library functions of the virtual machine. This allows C-Sheep programs to be compiled into an executable using a normal off-the-shelf C/C++ compiler. This executable can then be run from within the native working environment of the operating system. The purpose of this library is to simplify the migration from the educational mini-language to real-world systems by allowing novice programmers to make an easy transition from using the C-Sheep system to using the C programming language

The ISIS Project: Real Experience with a Fault Tolerant Programming System

The ISIS project has developed a distributed programming toolkit and a collection of higher level applications based on these tools. ISIS is now in use at more than 300 locations world-wise. The lessons (and surprises) gained from this experience with the real world are discussed