Re: How come Ada isn't more popular?

[<adaworks@sbcglobal.net>]

"kevin cline" <kevin.cline@gmail.com> wrote in message >
> Yes, I've read that article.  It would really be sad if Ada were not
> superior to C for a toy problem in embedded control system development,
> since Ada was designed specifically for that purpose.  But the point
> was that expressiveness drives programmers to new languages, and Ada
> isn't particularly expressive.
>
It depends on what you want to express.   Expressiveness, like beauty,
is often "in the eye of the beholder."  For many software professionals,
the absence of curly-braces makes a language less expressive.  For
others, their presence is a problem.   For some, brevity is a sign of
expressiveness.  For others, ease of understanding on the part of a
reader is important to expressiveness.

I do know a lot of languages, including many in the C family.  I have
programmed in COBOL, Fortran, PL/I, BASIC, Python, and many
others.   I teach a class in comparative programming languages.

An important distinction to be made is expressibility versus expressiveness.
The fact that I can express a solution in Fortran that is better suited to being
expressed in COBOL does not mean that Fortran is expressive.   When
a solution is possible, that makes it expressible.  When the language is
designed to express such solutions, that makes it expressive -- for that
kind of problem.

Languages evolve to become more expressive.  Fortran has evolved.  COBOL
has evolved.  Ada has evolved.  Even Java continues to evolve.  Some languages
seem not to evolve and remain stagnent.  PL/I comes to mind.   Some programmers
do not evolve, and they also become out-of-date.


As languages evolve some tend to get better at being more directly expressiveof
a larger range of solutions.  Not all languages evolve well.   In my view, C++
has not become better with its most recent "improvements."

Ada is expressive of a large number of solutions that are more difficult to
express in C or other languages.  However, the base language is not as
expressive as Perl for regular expressions.  That has required a separate
library unit.  It is not as directly expressive of mathematical solutions as
Fortran.  That too requires library units.    All the fundamental constructs
are in place to create powerful library units.  This capability allows the
language to be easily extended to accomodate a large number of kinds
of solutions.  Expressiveness is, for some kinds of solutions, through the
creation of such libraries, not by burdening the language.

The type model of Ada does enhance expressiveness since it allows a
lot of extensions.   There are certainly things I would do differently in
that type system, and future languages will come along that improve on
Ada.  At present, that has not happened -- certainly not with a type
model that I like.   The visibility rules of Ada allow some powerful
constructs for designing large-scale software systems.   None of the
C family, including C++, is as expressive in this regard.

Expressiveness needs to be considered beyond toy programs.  Real
software systems also evolve.  The fact that I can program myself
into a corner with some simple code that needs to be rewritten from
scratch each time the problem changes a little, can give me the
illusion of expressiveness.  Real expressiveness includes the ability to
easily adapt the software in-place to the changing realities of the
environment in which it is deployed.

With all its shortcomings, and it does have shortcomings, Ada seems to
be have the capacity for being expressive of most kinds of practical
software solutions.  For many of those solutions, without supporting
libraries, it is characterized by expressibility.  When one adds libraries
written in Ada, we see greater expressiveness.

Expressiveness is not always hampered by the language design but
by those who have not yet learned how to use that design as it was
intended to be used.

Richard riehle