Re: Inheritance versus Generics

[dewar@merv.cs.nyu.edu (Robert Dewar)]

Bob Duff said

<<In article <336596D9.2781E494@eiffel.com>,
  Bertrand Meyer  <bertrand@eiffel.com> wrote:
  >Large-scale practical experience with a language cannot hurt, of
  >course, but (posited) lack thereof does not disqualify one from
  >talking about the language.

  I tend to agree with Bertrand Meyer here.  I mean, I've criticized some
  aspects of Eiffel without having written a line of code in Eiffel (well,
  at least not something serious).  But I've at least read the language
  definition carefully.

I am just stating a rule that comes from a lot of experience. I have
all too often seen experts in this field make statements about languages
they do not know well enough. Often these comments are just factually
incorrect. I could give lots of examples, with lots of famous names, but
that seems perhaps inappropriate :-)

Anyway, it is a rule I follow for myself. I have seen far too many people
who should know better make completely ridiculous statements about languages
they do not know well enough -- this is particularly true for lesser known
languages such as COBOL (I mean of course lesser known among the language
design crowd :-)

I have also seen plenty of absurd statements about C++ by Ada advocates,
and plenty of absurd statements about Ada by all sorts of people.

Anyway, I follow the rule myself, you won't see me criticizing Eiffel until
such time as I have done some substantial programming in that language for
example.

Yes, it makes it harder to compare languages, but I still find it a very
useful rule in filtering out objective observsations from subjective wishes.
Language design is full of advocacy from people who urgently wish language
X to be the best, and are consequently blinder than they should be to
shortcomings of X, and strenghts of (not X).

Going back to the quote, my concern is NOT with people who don't know
anything, it is with experts who just don't have enough working familiarity
with how a language is actually used in practice. This is a very important
aspect of understanding a language design. This cannot be obtained from
reading a reference manual.

  <<Perhaps Robert Dewar is (over)reacting to those who criticize Ada
  without knowing the first thing about it.  I don't think Meyer is one of
  those.>>


By the way, please note that I did not, and did not intend to specifically
suggest Betrand as someone who made incorrect statements, and I have made
no such statement. Bertrand added his own name to the thread in his
follow up :-) I certainly did not say that Bertrand knows nothing about
Ada, and I sure hope he did not take me to be saying that.

I also do not say that anything disqualifies anyone from talking about
anything! All I am saying is that I value comments more from people who
have the practical experience to go along with their theoretical 
understanding. And that I apply this to myself, so if you see a comment
from me criticizing a language, then it means I have written substantial
amounts of code in the language (substantial = for me large scale
delivered commercial code). 

(unless of course my evil twin brother has been masquerading as me again
and violating this rule :-)


Robert