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List of Names
- Language type:
Ada is a block-structured language with many
object-oriented programming features. It
was originally designed for the US Dept. of Defense,
and was intended to support large-scale programming
and promote software reliability. Some of Ada's
features include: nested procedures, nested packages,
strong typing, multi-tasking, generics,
exception handling, and
abstract data types.
Primitive data types supported by Ada
include a variety of numeric types, booleans,
characters, references, and enumerated
symbols. Arrays, records (structures),
and strings are Ada's composite types.
With its emphasis on program safety, it is
not surprising that Ada is a strongly typed
language: all data elements must be declared
as storing a particular type or subtype, and
type enforcement is strictly applied both
within and between modules.
Ada supports a full complement of
sequential control structures, as well as
comprehensive exception handling.
Ada is very strictly standardized and
well documented as a language. Ada
compilers undergo stringent validation
with an official test suite. At least one
free Ada compiler and several good
commercial ones are
Ada was named in honor of Lady Ada Lovelace (1815-1852), a
friend and confidante of Charles Babbage.
Ada was initially standardized in 1983, and was
superseded by a new standard in 1995. These
two versions are now known as Ada 83
and Ada 95.
Jean Ichibah et al, 1978-1983.
- See Also:
Ada is a fairly complex language. It has
a conventional but very rich Pascal-like
syntax, with many specialized features.
The best aspects of Ada are its support
for generics (templates), its support
for task synchronization, and its
very good exception handling. Its
worst features are its complex syntax,
and the poor performance of the code
generated by most early compilers.
(by the late 1980s, compilers had
improved, and modern Ada compilers
generate code as fast or ever faster
than that emitted from C or Fortran
Note that Ada's semantics include range
checking on all integer types, and
bounds checking on all arrays; these
program safety constraints slowed down
early compilers (later ones got better
at it, and also added support for
compiler directives and pragmas that
disabled certain checks in final release
compilers tend to be very very strict,
but if you ever got your program to
compile you could be pretty sure it would
at least do something comprehensible
(unlike, for example, C).
Originally, Ada was designated as the ONLY
language to be used for US DoD software
development. This policy never really
caught on, and by 1997 the rule was
rescinded. Basically, the Defense
Information Systems Agency (DISA) realized
that even a language as painstakingly
designed as Ada could not be a panacea.
- Sample code:
-- simple programming with floating-point #s
procedure Think is
A, B : Float := 0.0; -- A and B initially zero; note the period.
I, J : Integer := 1;
A := B * 7.0;
I := J * 3;
B := Float(I) / A;
Descriptions in this dictionary are ©1997-99 Neal Ziring. Some
examples copyright of their respective authors. Some
technologies and languages are trademarked. Permission to
copy descriptions is granted as long as authorship credit is preserved.
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Dictionary and script maintained by Neal Ziring, last major modifications 3/18/98. Most recent
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