ada 95 and visual technology (Leonid Dulman)

ada 95 and visual technology (Leonid Dulman)

[dulman]

                      Ada 95 AND VISUAL TECHNOLOGY
                      ----------------------------
                            By Leonid Dulman

     The development of visual programming systems today is the most

dynamic and quickly developing part of tool software. It is today

possible to speak about a new algorithm-programming meta-language - VISUAL

LANGUAGE, which operates with forms, properties, methods and events.

   Its main objects utilize quite standard shapes which are similar in

diverse VISUAL systems from VISUAL BASIC to VISUAL REXX.

   System-independence is characteristic  of VISUAL METALANGUAGE (graphic

images have identical imaging in MS-WINDOWS, in OS/2, and in UNIX), but it is

also adaptable to some of the existing programming languages. But since

VISUAL METALANGUAGE is a strictly structured language with adequate object

oriented programming capability, its specific realization can not strictly

apply to all visual languages. For instance, it is difficult to speak about

language REXX as a structural programming language.

    VISUAL TECHNOLOGY has most completely connected the designing and

programming software processes. VISUAL SYSTEMS used today have been used for

the entire draft work related to the VISUAL interface development between

the program and operating system. Thus for a programmer, working with VISUAL

BASIC or DELPHI, it is not necessary to know all the WINDOWS details, which

are built in to the tools . At the same time we need to emphasize, that the

decisions regarding of a specific problem cannot be executed entirely by

means of VISUAL tools and part of the code must be written manually.

    It is on the other hand rather desirable, that developed software should

work in various operating systems, especially for information retrieval

systems, REAL TIME systems, and others where the various software parts

are executed on various computers and in various operating environments

(PC, MAINFRAME, VAX).

    Two desireable features of VISUAL systems are:

    1. The programming language should support OOP;

    2. The language should be standard and system independent as much as
       possible.

    The first property is provided by many languages (and practically all

dialects with prefix OBJECT). The second is provided by only one programming

language, Ada 95. It is the sole language which does not change depending on

the compiler developer firm and on the operating system. Moreover Ada 95

compilers must pass validation tests so that the generated object code has

a higher probability of being correct.

    Principles of object-oriented programming have found in Ada 95 their

most consistent and complete realization. The VISUAL objects types represent

a packages tree. The object structure is described by TAGGED RECORD and

form CLASS for all types derivative from it, but properties and methods

are realized by means of PRIMITIVE OPERATION on parent objects. Thus is

provided DISPATCHING and OVERLOAD of the objects operations ( In DELPHI the

properties names coincide with the class component names and for the

operation ":=", there is no strict definiteness. There is no clearly

understood calling property or public component significance).

    In Ada 95, for PRIVATE type objects, direct access is impossible and

their state may be changed only by calling authorized operations.

    The events mechanism can be realized directly. The language supports

parallel data processing and does not depend on the operating system for

the processes mechanism (they are realized on RUN TIME level).

    Each VISUAL object represents a separate process which can be in passive

or active state (receives INPUT FOCUS). The system permanently manages the

condition and interaction of these processes. If a programming language

is not able to manage these processes itself (C ++, PASCAL), these

functions are managed by operating system and the software becomes dependant

on the operating environment . Ada 95, having task mechanisms, can manage

processes independently , therefore the software developed with it can

stand-alone. This property of the language must be provided for REAL TIME

and DIRECT CONTROL systems, if we want successful software operable

on various OS.

    Though many serious software developers look down today on the PC/DOS,

OS/2 or WINDOWS, these systems are often used first at the start of large

project development. They are used for emulation, for modeling software

for debugging, and for testing of such programs. They are also used secondly

even for the built-in microprocessor systems where visualization means

are needed (even electronic watches have a dial).

    Ada 95 today is a unique language for distributed systems development

on multiprocessor complexes.

    For Remote Client/Server networks, it is possible to develop indivisible

and unified software instead of various software bits and pieces, thereby

much increaseing its reliability and stability. The access to a database on

the language level (PROTECTED TYPE) helps ensure a high degree of data

reliability, absence of conflict, and safety.

    We shall consider an example( non ada) :

    Client A reads out some information INF1 from the database and uses it

in forming INF2. During this process, if the data INF2 are accessible to

read, Client B reads INF2 and updates data INF3. After Client A and

Client B finish the process of data updating , the database will appear

destroyed because of incompatibility INF2 and INF3.

  It is impossible in ADA 95 ENTRY mechanism.

    It seems to me that for the above reasons it is apparent that

Ada 95 is an excellent base for the development of VISUAL systems today. It

is easy to learn and provides a tool for developing beautiful,and reliable

software. The availability in the near future of new Ada 95 VISUAL

systems such as ActivAda, IntegrAda and Janus Ada will provide a serious

alternative to VISUAL BASIC, DELPHI and OBJECT C ++.

ada 95 and visual technology (Leonid Dulman)

[dulman]

                      Ada 95 AND VISUAL TECHNOLOGY
                      ----------------------------
                            By Leonid Dulman

     The development of visual programming systems today is the most
dynamic and quickly developing part of tool software. It is today
possible to speak about a new algorithm-programming meta-language - VISUAL
LANGUAGE, which operates with forms, objects,properties, methods and events.
   Its main objects utilize quite standard shapes which are similar in
diverse VISUAL systems from VISUAL BASIC to VISUAL REXX.
   System-independence is characteristic  of VISUAL METALANGUAGE (graphic
images have identical imaging in MS-WINDOWS, in OS/2, and in UNIX), but it is
also adaptable to some of the existing programming languages. But since
VISUAL METALANGUAGE is a strictly structured language with adequate object
oriented programming capability, its specific realization can not strictly
apply to all visual languages. For instance, it is difficult to speak about
language REXX as a structural programming language.
    VISUAL TECHNOLOGY has most completely connected the designing and
programming software processes. VISUAL SYSTEMS used today have been used for
the entire draft work related to the VISUAL interface development between
the program and operating system. Thus for a programmer, working with VISUAL
BASIC or DELPHI, it is not necessary to know all the WINDOWS details, which
are built in to the tools . At the same time we need to emphasize, that the
decisions regarding of a specific problem cannot be executed entirely by
means of VISUAL tools and part of the code must be written manually.
    It is on the other hand rather desirable, that developed software should
work in various operating systems, especially for information retrieval
systems, REAL TIME systems, and others where the various software parts
are executed on various computers and in various operating environments
(PC, MAINFRAME, VAX).

    Two desireable features of VISUAL systems are:

    1. The programming language should support OOP;
    2. The language should be standard and system independent as much as
       possible.

    The first property is provided by many languages (and practically all
dialects with prefix OBJECT). The second is provided by only one programming
language, Ada 95. It is the sole language which does not change depending on
the compiler developer firm and on the operating system. Moreover Ada 95
compilers must pass validation tests so that the generated object code has
a higher probability of being correct.
    Principles of object-oriented programming have found in Ada 95 their
most consistent and complete realization. The VISUAL objects types represent
a packages tree. The object structure is described by TAGGED RECORD and
form CLASS for all types derivative from it, but properties and methods
are realized by means of PRIMITIVE OPERATION on parent objects. Thus is
provided DISPATCHING and OVERLOAD of the objects operations ( In DELPHI the
properties names coincide with the class component names and for the
operation ":=", there is no strict definiteness. There is no clearly
understood calling property or public component significance).
    In Ada 95, for PRIVATE type objects, direct access is impossible and
their state may be changed only by calling authorized operations.
    The events mechanism can be realized directly. The language supports
parallel data processing and does not depend on the operating system for
the processes mechanism (they are realized on RUN TIME level).
    Each VISUAL object represents a separate process which can be in passive
or active state (receives INPUT FOCUS). The system permanently manages the
condition and interaction of these processes. If a programming language
is not able to manage these processes itself (C ++, PASCAL), these
functions are managed by operating system and the software becomes dependant
on the operating environment . Ada 95, having task mechanisms, can manage
processes independently , therefore the software developed with it can
stand-alone. This property of the language must be provided for REAL TIME
and DIRECT CONTROL systems, if we want successful software operable
on various OS.
    Though many serious software developers look down today on the PC/DOS,
OS/2 or WINDOWS, these systems are often used first at the start of large
project development. They are used for emulation, for modeling software
for debugging, and for testing of such programs. They are also used secondly
even for the built-in microprocessor systems where visualization means
are needed (even electronic watches have a dial).
    Ada 95 today is a unique language for distributed systems development
on multiprocessor complexes.
    For Remote Client/Server networks, it is possible to develop indivisible
and unified software instead of various software bits and pieces, thereby
much increaseing its reliability and stability. The access to a database on
the language level (PROTECTED TYPE) helps ensure a high degree of data
reliability, absence of conflict, and safety.
    We shall consider an example( non ada) :
    Client A reads out some information INF1 from the database and uses it
in forming INF2. During this process, if the data INF2 are accessible to
read, Client B reads INF2 and updates data INF3. After Client A and
Client B finish the process of data updating , the database will appear
destroyed because of incompatibility INF2 and INF3.
    It is impossible in ADA 95 ENTRY mechanism.
    It seems to me that for the above reasons it is apparent that
Ada 95 is an excellent base for the development of VISUAL systems today. It
is easy to learn and provides a tool for developing beautiful,and reliable
software. The availability in the near future of new Ada 95 VISUAL
systems such as ActivAda, IntegrAda and Janus Ada will provide a serious
alternative to VISUAL BASIC, DELPHI and OBJECT C ++.