Forms / 3 – Forms / 3 is an example of LPV based on the spreadsheet paradigm, implemented by Margaret Burnett in 1991, as a prototype of her dissertation work.
In this case, the programmer realizes his program by creating a form and specifying its content.
This paradigm is commonly used in commercial spreadsheets, where the form is in the form of a marked grid, and the content is specified by the cell formulas.
Forms / 3 programs include formulas (spreadsheets) with cells, except that the cells are not embedded in a grid. A Forms / 3 programmer creates a program by directly manipulating the cells to place them on the form and defining a formula for each cell by using a flexible combination of pointing, typing, and gestures.
The calculations of a program are completely determined by these formulas. The formulas are combined in a (unidirectional) network of constraints, and the system continually ensures that all values displayed on the screen satisfy these constraints.
Forms / 3 is a complete Turing language. Its purpose is to increase the usefulness of the concept of the spreadsheet concept by supporting the advanced functionalities necessary for programming.
Thus, it supports facilities such as graphics, animation, and recursion, but without resorting to macros to change the state of connections to the traditional programming languages.
For example, Forms / 3 offers a rich and extensible type collection by allowing the attributes of a type to be defined by formulas, and an instance of a type to be the value of a cell, which can be referred to as a cell.
The “concrete” facility is present in that the resulting graphic element is seen as soon as sufficient formulas have been offered to make this possible. The “direct” feature is present through the direct manipulation mechanism for specifying the graphic element because the programmer demonstrates the specifications directly on the created graphic element.
The target group of Forms / 3 are the “future” programmers, meaning those whose job it will be to create applications, but whose training has not emphasized the current traditional programming languages.
A goal of Forms / 3 was to reduce the number and complexity of the mechanisms required for programming applications, with the hope that programmers will find them easier than if they used traditional languages, and programming will be more accurate and / or accelerated.
In empirical studies, programmers have shown higher accuracy and speed in both program creation and debugging, using Forms / 3 compared to a variety of alternative techniques.
Prograph – Visual programming with data streams
Prograph was designed in 1983 by Tomasz Pietrzykowski and Philip T. Cocs. The second one that remained in the project for a long time brought improvements over the years. Prograph is an LPV based on data streams for professional programmers.
The paradigm based on data flows the modality of visual programming widely used in the industry, but also of the visual programming environments for certain fields, such as scientific visualization systems and simulation systems.
Prograph is a functional and easy-to-use language. The data are represented bylines and the methods by various rectangles. Each rectangle contains nodes for inputs and outputs. Data is transmitted by values, which allows the methods to use as inputs, the outputs from other methods. Prograph does not have variables, but only data that “flows” through methods.
Prograph is a complete Turing programming language, that is, any program that can be written in C ++ or any other high-level language can also be written in Prograph. Programs are created by building data flow charts within the editor. Prograph classes, methods, and attributes are graphically represented and manipulated.