Re: Surprise in array concatenation

[<adaworks@sbcglobal.net>]

"Randy Brukardt" <randy@rrsoftware.com> wrote in message
news:zcKdnQ0Er8bYF6neRVn-qQ@megapath.net...
> <adaworks@sbcglobal.net> wrote in message
> news:zSFTe.4078$wk6.1150@newssvr11.news.prodigy.com...
> > I recall a project where an Ada newbie, having learned about enumerated
> > types, created one enumerated type that was three pages long.  That is,
> > the number of values in the type was so great that it took three pages
> > of 11 X 14 standard printer paper to contain it.
>
> Hey, I resemble that remark!
>
> The intermediate code definition for Janus/Ada includes an enumeration of
> 300 or so operations. The definition covers several pages (it has comments).
> That's used as the discriminant on a giant variant record that covers more
> than 6 pages. No newbies here. :-)
>
I did not mean to cast any aspersions on the knowledge and skill of those
who use enumerated types intelligently.   Rather, I meant to indicate that
enumerated types can be easily misused by those who are not thinking
about their life-cycle consequences.

In the project I was referencing, we had a large number of packages that
depended on the extra long enumeration type.  The enumeration type was
a list of weapon systems that could be engaged as necessary.   Every time
a new weapon was added, the entire system had to be recompiled.   I suggested,
and the project members agreed, that a table of weapons that could be
updated outside the software would give us greater flexibility.

One of the key problems in all of software practice is designing for
extensibility
and maintainability.    We want our software solutions to evolve gracefully,
over time, into more fully-featured systems, but we would like this to occur
without having to do the equivalent of "open-heart"  surgery every time a
new feature is required.    Enumerated types can have the effect of painting
one's self in to a corner.

Richard Riehle