program design and analysis
integrated program development system
finely grained hypertext
Virtual Reality Modeling Language
A. P. Gagarin, A. D. Golubkin
Recent integrated program development environments provide large amount of means for precise and quick obtaining of inquiry information about the program under consideration for sake of its perusal, debugging and development. Using these means programmer can build on the computer screen an up-to-date inquiry environment that assists him by making possibly quick and proper decisions. Nevertheless, due to some peculiarities of window implementation in current operating systems the user is doomed to a lot of manipulations necessary to adapt windows to his needs. These manipulations are: locating on the screen, specifying its size and scrolling to the required content. Therefore, an effective set-up of the inquiry environment for a programmer remains to be a topical problem.
Some solutions of the problem are considered in the issue on the base of a «finely grained» hypertext. A hypertext can be called «finely grained», if scope of the observer contains not less than 10 nodes, each one containing relatively short linear text (no more than 10 lines and no more than 50 characters per line).
Text editor «Rumex» is intended for creating, saving and retrieval of finely grained hypertext documents. As an example, the issue contains a presentation of a program in the editor window as 2-dimensional map of nodes and links onto a flat (2-dimensional) sheet. The example indicates that the properties of finely grained hypertext in its flat 2-dimensional version let successfully apply such a hypertext for source program representation, especially, if the programs are well structured.
The option of provisory hiding of nodes as long as they are not needed for the current stage of program analysis is a source for increasing of information density by program text representation and preserving thereby program’s structure discernible. It is important, that the manipulations needed to hide and display nodes and links should be reiterated as mutually coordinated sequences. The duty makes programmer to slow down and distracts him from the creative tasks.
It is proposed for reducing of the expanses to move from 2-dimensional to 3-dimensional (3-D) hypertext, which is understood as placing of hypertext nodes an links into 3-dimension space, simulated on a computer display by special program means.
The simplest way of transforming a 2-dimensional hypertext into 3-dimensional one is a distribution of the nodes as flat rectangles among parallel planes. The nodes may thereby have no visible thickness. In this case changing of the visual angle makes shielded nodes became visible in addition to those nodes that shielded them before. Visual angle changing proceeds quickly due to low number of needed manipulations and complies also with the subconscious faculty of a human for orientation in the physical space engaging his attention to a very slight degree.
This kind of the 3-D hypertext reveals as its shortcomings that the number of links displayed by lines does not go down as compared with the corresponding 2-dimensional hypertext, and nodes shield links.
Other kind of the 3-D hypertext is constructed from 3-dimensional nodes shaped as parallelepipeds with text placed on all or some part of their facets. It inherits all advantages of the 3-D hypertext considered previously, but permits to reduce some part of links displayed by lines, as well as to see the rest of links in detail. Constructing the 3-D hypertext with 3-D links urges to distribute the text content among facets of the 3-D nodes. The issue contains advices how the problem could be solved.
In any case to construct a 3-D representation of a program, it is necessary to perform following steps:
representing the program as 2-dimensional hypertext in the editor «Rumex»;
transforming the hypertext into text on the Virtual Reality Modeling Language (VRML);
displaying the hypertext by the program «Cartona-3D».