Re: Child packages

[Robb.Nebbe@di.epfl.ch (Robb Nebbe)]

In article <EACHUS.94Oct17115240@spectre.mitre.org>, eachus@spectre.mitre.org (Robert I. Eachus) writes:
|> In article <1994Oct17.091621@di.epfl.ch> Robb.Nebbe@di.epfl.ch (Robb Nebbe) writes:
|> 
|>  > But you have to want to shoot yourself in the foot. I would think it
|>  > would be almost impossible to "accidently" declare a child package
|>  > and muck around with private information.
|> 
|>    Never underestimate stupidity, you can't overestimate it.
|> 
|>    "Against stupidity, the Gods themselves contend in vain." Schiller(sp?)
|> 
|>    You have to know why it is a bad thing. There are no warning signs
|> posted.  And I don't expect people to spend lots of effort adding
|> comments to package specifications explaining what catastrophes can be
|> created by illegitimate children.
|> 

It is sort of like a rail at the edge of a cliff to keep people
from falling off. Something simple is sufficient but if you want
to worry about all the really stupid people then maybe you should
put up a 12 foot high barier in plexiglass or something. I think
that would really enhance places like the Grand Canyon. :-)

I find that child packages make my code safer. They frequently 
replace things like unchecked conversion where I know that it
will always work but I couldn't get Ada83 to check it without
giving up information hiding. I feel a little safer knowing that
the compiler can check everything and that some accidental error
didn't slip in when I had to use unchecked conversion.

As far as illegitemate child packages I find that there are plenty
of warning signs along the way. To write a child package you have to
preference the package name with the name of the parent(s). When
you with the package you have to give the full name including the
parent(s).

I don't buy the arguement that a stupid programmer might declare a
child package by accident. That a programmer might do something
wrong on purpose seems more like paranoia than anything worth
getting concerned about.

A version control system seems like a much better place to worry
about who can do what to which packages.

- Robb Nebbe