<s>
Automata-based	B-Application
programming	I-Application
is	O
a	O
programming	O
technology	O
.	O
</s>
<s>
Its	O
defining	O
characteristic	O
is	O
the	O
use	O
of	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
to	O
describe	O
program	O
behavior	O
.	O
</s>
<s>
The	O
transition	O
graphs	O
of	O
state	B-Architecture
machines	I-Architecture
are	O
used	O
in	O
all	O
stages	O
of	O
software	B-Application
development	O
(	O
specification	O
,	O
implementation	O
,	O
debugging	O
and	O
documentation	O
)	O
.	O
</s>
<s>
Automata-based	B-Application
programming	I-Application
technology	O
was	O
introduced	O
by	O
Anatoly	O
Shalyto	O
in	O
1991	O
.	O
</s>
<s>
Switch-technology	O
was	O
developed	O
to	O
support	O
automata-based	B-Application
programming	I-Application
.	O
</s>
<s>
Automata-based	B-Application
programming	I-Application
is	O
considered	O
to	O
be	O
rather	O
general	O
purpose	O
program	O
development	O
methodology	O
than	O
just	O
another	O
one	O
finite	B-Architecture
state	I-Architecture
machine	I-Architecture
implementation	O
.	O
</s>
<s>
The	O
main	O
idea	O
of	O
suggested	O
approach	O
is	O
to	O
construct	O
computer	B-Application
programs	I-Application
the	O
same	O
way	O
the	O
automation	O
of	O
technological	O
processes	O
(	O
and	O
other	O
kinds	O
of	O
processes	O
too	O
)	O
is	O
done	O
.	O
</s>
<s>
For	O
all	O
that	O
on	O
the	O
basis	O
of	O
data	O
domain	O
analysis	O
the	O
sources	O
of	O
input	O
events	O
,	O
the	O
control	O
system	O
(	O
the	O
system	O
of	O
interacting	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
)	O
and	O
the	O
control	O
objects	O
implementing	O
output	O
actions	O
are	O
singled	O
out	O
.	O
</s>
<s>
These	O
control	O
objects	O
can	O
also	O
form	O
yet	O
another	O
type	O
of	O
input	O
actions	O
that	O
are	O
transmitted	O
through	O
a	O
feedback	O
from	O
control	O
objects	O
back	O
to	O
the	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
.	O
</s>
<s>
In	O
recent	O
years	O
great	O
attention	O
has	O
been	O
paid	O
to	O
the	O
development	O
of	O
the	O
technology	O
of	O
programming	O
for	O
embedded	B-Architecture
systems	I-Architecture
and	O
real-time	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
These	O
systems	O
have	O
special	O
requirements	O
for	O
the	O
quality	O
of	O
software	B-Application
.	I-Application
</s>
<s>
One	O
of	O
the	O
best	O
known	O
approaches	O
for	O
this	O
field	O
of	O
tasks	O
is	O
synchronous	B-Language
programming	I-Language
.	O
</s>
<s>
Simultaneously	O
with	O
the	O
advance	O
of	O
synchronous	B-Language
programming	I-Language
in	O
Europe	O
,	O
an	O
approach	O
to	O
software	B-Application
development	O
for	O
crucial	O
systems	O
called	O
automata-based	B-Application
programming	I-Application
or	O
state-based	O
programming	O
was	O
being	O
created	O
in	O
Russia	O
.	O
</s>
<s>
The	O
term	O
event	B-Application
is	O
being	O
used	O
more	O
and	O
more	O
widely	O
in	O
programming	O
;	O
recently	O
it	O
has	O
become	O
one	O
of	O
the	O
most	O
commonly	O
used	O
terms	O
in	O
software	B-Application
development	O
.	O
</s>
<s>
As	O
opposed	O
to	O
it	O
,	O
the	O
offered	O
approach	O
is	O
based	O
on	O
the	O
term	O
state	B-Application
(	O
State-Driven	O
Architecture	O
)	O
.	O
</s>
<s>
After	O
introduction	O
of	O
the	O
term	O
input	O
action	O
,	O
which	O
could	O
denote	O
an	O
input	O
variable	O
or	O
an	O
event	B-Application
,	O
the	O
term	O
automaton	O
without	O
outputs	O
might	O
be	O
brought	O
in	O
.	O
</s>
<s>
It	O
is	O
the	O
finite	B-Architecture
deterministic	I-Architecture
automaton	I-Architecture
.	O
</s>
<s>
That	O
is	O
why	O
,	O
the	O
sort	O
of	O
programming	O
,	O
which	O
is	O
based	O
on	O
this	O
term	O
,	O
was	O
called	O
“	O
automata-based	B-Application
programming	I-Application
”	O
.	O
</s>
<s>
So	O
the	O
process	O
of	O
software	B-Application
creation	O
could	O
be	O
named	O
“	O
automata	O
software	B-Application
design	O
”	O
.	O
</s>
<s>
In	O
order	O
to	O
distinguish	O
the	O
nodes	O
of	O
these	O
graphs	O
the	O
term	O
state	B-Application
coding	O
has	O
been	O
introduced	O
.	O
</s>
<s>
With	O
multivalued	O
state	B-Application
coding	O
a	O
single	O
variable	O
can	O
be	O
used	O
to	O
distinguish	O
states	O
of	O
automaton	O
,	O
the	O
number	O
of	O
states	O
is	O
equal	O
to	O
the	O
number	O
of	O
values	O
this	O
variable	O
can	O
take	O
on	O
.	O
</s>
<s>
This	O
allowed	O
introducing	O
of	O
the	O
term	O
program	O
observability	O
(	O
that	O
is	O
,	O
the	O
value	O
of	O
the	O
state	B-Application
variable	O
can	O
be	O
checked	O
)	O
.	O
</s>
<s>
Using	O
the	O
concept	O
of	O
“	O
state	B-Application
”	O
in	O
contrast	O
to	O
the	O
concepts	O
of	O
“	O
events	O
”	O
and	O
“	O
variables	O
”	O
,	O
allows	O
one	O
to	O
understand	O
and	O
to	O
specify	O
the	O
task	O
and	O
its	O
parts	O
(	O
subtasks	O
)	O
more	O
clearly	O
.	O
</s>
<s>
It	O
is	O
necessary	O
to	O
note	O
that	O
using	O
automata-based	B-Application
programming	I-Application
implies	O
debugging	O
by	O
drawing	O
up	O
the	O
protocols	O
(	O
logging	O
)	O
in	O
terms	O
of	O
automata	O
.	O
</s>
<s>
For	O
this	O
approach	O
there	O
is	O
a	O
formal	O
and	O
isomorphic	O
method	O
of	O
transforming	O
from	O
the	O
transition	O
graph	O
to	O
the	B-Application
software	I-Application
source	O
code	O
.	O
</s>
<s>
So	O
when	O
using	O
high-level	B-Language
programming	I-Language
languages	I-Language
,	O
the	O
simplest	O
way	O
is	O
to	O
use	O
a	O
construct	O
which	O
is	O
similar	O
to	O
the	O
switch	O
construct	O
of	O
the	O
C	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
That	O
is	O
why	O
the	O
first	O
implementation	O
of	O
automata-based	B-Application
programming	I-Application
was	O
called	O
“	O
Switch-Technology	O
”	O
.	O
</s>
<s>
Additional	O
information	O
about	O
automata-based	B-Application
programming	I-Application
can	O
be	O
found	O
in	O
the	O
“	O
Switch-technology	O
”	O
article	O
.	O
</s>
<s>
Nowadays	O
automata-based	B-Application
programming	I-Application
has	O
been	O
developed	O
in	O
several	O
ways	O
,	O
for	O
different	O
types	O
of	O
task	O
to	O
be	O
solved	O
and	O
for	O
various	O
type	O
of	O
computing	O
devices	O
.	O
</s>
<s>
Russian	O
registration	O
certificate	O
was	O
issued	O
for	O
the	O
Automata-based	B-Application
programming	I-Application
core	O
and	O
for	O
the	O
Automata-based	B-Application
programming	I-Application
plug-in	O
for	O
Eclipse	B-Application
IDE	I-Application
.	O
</s>
<s>
In	O
such	O
systems	O
there	O
are	O
no	O
events	O
,	O
but	O
input	O
and	O
output	O
actions	O
are	O
binary	O
variables	O
and	O
operating	B-General_Concept
system	I-General_Concept
is	O
working	O
in	O
the	O
scanning	O
mode	O
.	O
</s>
<s>
Systems	O
of	O
this	O
class	O
are	O
usually	O
to	O
be	O
implemented	O
on	O
programmable	B-Architecture
logic	I-Architecture
controllers	I-Architecture
,	O
which	O
have	O
relatively	O
small	O
amount	O
of	O
memory	B-General_Concept
and	O
programming	O
is	O
to	O
be	O
performed	O
using	O
specialized	O
languages	O
(	O
for	O
example	O
,	O
the	O
language	O
of	O
ladder	O
schemes	O
or	O
functional	O
blocks	O
)	O
.	O
</s>
<s>
Henceforth	O
automata	O
approach	O
was	O
spread	O
to	O
the	O
event-based	B-Application
(	O
reactive	O
)	O
systems	O
.	O
</s>
<s>
Any	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
could	O
be	O
used	O
as	O
an	O
environment	O
.	O
</s>
<s>
The	O
automata	O
implementation	O
of	O
event-based	B-Application
systems	O
was	O
made	O
with	O
the	O
help	O
of	O
the	O
procedural	B-Application
approach	I-Application
to	O
software	B-Application
development	O
,	O
hence	O
the	O
name	O
“	O
state-based	O
programming	O
”	O
.	O
</s>
<s>
One	O
of	O
the	O
features	O
of	O
such	O
approach	O
to	O
programming	O
for	O
the	O
reactive	O
systems	O
is	O
that	O
the	O
centralization	O
of	O
program	O
logic	O
is	O
achieved	O
by	O
liquidation	O
of	O
logic	O
in	O
the	O
event	B-Application
handlers	O
and	O
forming	O
of	O
system	O
of	O
interacting	O
automata	O
,	O
which	O
are	O
called	O
from	O
these	O
handlers	O
.	O
</s>
<s>
Automata	O
in	O
such	O
system	O
can	O
interact	O
by	O
nesting	O
,	O
by	O
ability	O
to	O
call	O
each	O
other	O
and	O
with	O
the	O
help	O
of	O
state	B-Application
numbers	O
interchange	O
.	O
</s>
<s>
All	O
this	O
allowed	O
to	O
start	O
the	O
Foundation	O
for	O
Open	O
Project	O
Documentation	O
,	O
in	O
the	O
context	O
of	O
which	O
many	O
projects	O
on	O
perfecting	O
of	O
automata-based	B-Application
programming	I-Application
are	O
being	O
developed	O
.	O
</s>
<s>
The	O
composite	O
approach	O
,	O
based	O
on	O
both	O
object-oriented	O
and	O
automata-based	B-Application
programming	I-Application
paradigms	O
,	O
may	O
be	O
rather	O
useful	O
for	O
solving	O
tasks	O
from	O
a	O
very	O
large	O
spectrum	O
.	O
</s>
<s>
This	O
approach	O
was	O
called	O
“	O
state-based	O
object-oriented	O
programming	O
”	O
.	O
</s>
<s>
The	O
main	O
feature	O
of	O
this	O
approach	O
is	O
that	O
,	O
like	O
in	O
Turing	B-Architecture
machines	I-Architecture
,	O
controlling	O
(	O
automata	O
)	O
states	O
are	O
explicitly	O
singled	O
out	O
.	O
</s>
<s>
The	O
minimal	O
set	O
of	O
documents	O
,	O
which	O
visually	O
and	O
clearly	O
describe	O
structural	O
(	O
static	O
)	O
and	O
behavioral	O
(	O
dynamic	O
)	O
sides	O
of	O
a	O
software	B-Application
project	O
,	O
is	O
described	O
.	O
</s>
<s>
A	O
new	O
state-based	O
approach	O
to	O
creation	O
of	O
algorithms	O
 '	O
visualizers	O
was	O
offered	O
.	O
</s>
<s>
Such	O
visualization	O
software	B-Application
is	O
widely	O
used	O
in	O
the	O
Computer	O
Technologies	O
department	O
of	O
Saint	O
Petersburg	O
State	B-Application
University	O
of	O
Information	O
Technologies	O
,	O
Mechanics	O
and	O
Optics	O
for	O
students	O
teaching	O
in	O
programming	O
and	O
discrete	O
mathematics	O
.	O
</s>
<s>
This	O
approach	O
allows	O
representing	O
of	O
visualizer	O
's	O
logic	O
as	O
a	O
system	O
of	O
interacting	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
.	O
</s>
<s>
Various	O
software	B-Application
tools	O
are	O
developed	O
to	O
support	O
automata	O
programming	O
.	O
</s>
<s>
This	O
tool	O
is	O
based	O
on	O
the	O
following	O
concepts	O
:	O
UML	B-Language
,	O
Switch-technology	O
,	O
Eclipse	B-Application
IDE	I-Application
,	O
Java	B-Language
programming	I-Language
language	I-Language
,	O
open	B-Application
source	I-Application
code	I-Application
(	O
)	O
.	O
</s>
<s>
All	O
this	O
enables	O
one	O
to	O
talk	O
about	O
the	O
UniMod	O
as	O
of	O
the	O
implementation	O
of	O
executable	B-Language
UML	I-Language
.	O
</s>
