Re: problems/risks due to programming language

[machaffi@fred.cs.washington.edu (Scott MacHaffie)]

In article <8126@hubcap.clemson.edu% billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu writes:
%From machaffi@fred.cs.washington.edu (Scott MacHaffie):
%% No, it is necessary to use a statement to indicate that the current case
%% statement is finished...like an "end case" or the next "when =% " in ADA.
%
%   Such a statement already exists: either the next "case Value:", or 
%   the } which ends the switch.  Why is it necessary to use a "break"?

example:
	switch (x) { /* x is a character, for example */
		case '0': case '1': ... case '9':
			print_digit(x);
			break;
		case 'a': ... case 'z':
			print_lowercase(x);
			break;
	}
The semantics of a C switch/case statement are different than the semantics
of an ada case/when.

%   The problem cannot simply be defined out of existence by saying,
%   in essence, that good programmers don't make mistakes.  All human
%   programmers make mistakes, and a well-designed language will help
%   to minimize this particular tendency.  In this case, C does not. 

Good programmers understand the language they are using -- good programmers
are literate. No language can eliminate errors. Good software engineering
practices should be used to (try to) catch language-specific errors.

%%%   This is certainly true; Brooks and others have noted that the good
%%%   software engineering practices which are routinely introduced in
%%%   conjunction with the Ada language are responsible for more of the 
%%%   resulting improvements than the fact that the Ada language was
%% 
%% Well, these practices are certainly NOT being introduced in the 
%% universities (at least not here).
%
%   In that case, I strongly suggest that you immediately bring 
%   this fact to the attention of the software engineering faculty 
%   at washington.edu.  At other universities (e.g., Clemson), Ada
%   *is* introduced in conjunction with software engineering.

Software engineering faculty?  I wish. None of the undergraduate classes
here touch software engineering, and I think at most one of the graduate
classes does. Anyone who wants to be a software engineer here has to
pick it up from other sources.

			Scott MacHaffie