Re: Practicalities of Ada for app development

[Nomen Nescio <nobody@dizum.com>]

> Metric's for expressive power are useful for comparing the languages
> fitness for a particular purpose. 

I don't agree. Expressive power is useful for comparing the /ease/ of
applying the language for a particular purpose. Domain specific languages
are always easy to apply to the problem domain, by definition. But that is
not the whole story. How easy it is to apply the language to solving a
particular problem doesn't take into account other possibly overriding
factors like maintainability, performance, etc. In other words, just because
it's easy to code a particular solution in a certain language doesn't mean
that language is ideal or even good for that solution in other respects.
Domain specific languages are often lacking in industrial strength features,
and are best for prototyping or programming in the small.

To take your point to the extreme, Perl and most other modern scripting
languages would never have had to be written, since SNOBOL4 from the late
sixties is more expressive and powerful than those new languages. But we see
there are other overriding concerns like facilities to handle large source
projects, the ability to employ namespaces, and other aspects of the newer
scripting languages that trade off the power and expressiveness of SNOBOL4
for modern management features and OO constructs, etc.

> E.g. if the purpose is filtering e-mail, it would be foolish to neglect to
> consider the language that probably has the single most expressive power
> for that kind of job (the procmail language).  The language was in fact
> specially designed just for that purpose.

SNOBOL4 can filter better than any language I have seen. If you're not happy
with that, most modern scripting languages have regexp facilities. What
makes one better than the other? There are other factors that lead us to
choose this or that language, and ease of application is helpful but not
essential. What's essential is a correct, serviceable solution that performs
adequately.

As long as a baseline functionality to get the job done exists in your
solution set of languages, you should consider other features that make
writing and maintaining good code easier.