An observation of Ada (may offend)

[bill@valiant.gmrc.gecm.com (R.A.L Williams)]

In article <1995Mar17.180137.9394@eisner> Larry Kilgallen wrote:
: In article <3kbkm1$41o@miranda.gmrc.gecm.com>, bill@valiant.gmrc.gecm.com (R.A.L Williams) writes:

: > b. No bit level manipulation (fixed in Ada95 but only for unsigned
: > ie. mod INTEGERs, I can't test a sign bit, not that I need to) HCTBAEL.

: Well some of us don't have Ada95 scheduled for our platforms...
: ...but I find that when I need to manipulate bits it is specific bit
: fields rather than generic bit-algebras :-).  Representation clauses
: in Ada are marvelous (although I have used similar capabilities from
: other languages which don't happen to be codified in their standards).

I agree that the representation clauses defined in the LRM are splendid,
the problem is that they are *optional*. I don't know what the situation
is now, but when I last did a lot of work in Ada many compilers had only
a fragmentary coverage. 

Most of the time, as you say, bit fields are adequate, but how would you
implement ECC alogorithms or maximal length sequence generators for instance?
So far as standards are concerned, I believe that bit fields are codified
in the ANSI C standard, and every ANSI C compiler I've used actually does
implement them.

: > e. No short cut operators (+= etc.) -- sorry, we've had this debate
: > already in another thread, I've heard the objections, I still like the
: > operators.

: I disagree, perhaps for a reason which has not been stated.  The 26 letters
: and the space bar are about all that I can touch-type.  Entering any
: punctuation requires looking at the keyboard, so I prefer long-cut
: operators.

Well, OK, but

  variable := variable + offset;

is 9 characters (not counting spaces for readability) longer than

  variable += offset;

I would also submit that, at least when the l-value gets more complex,
ie. array/structure dereference etc., that the short cut version is more
readable. For a simple statement like the example above there's no real
difference in readability. For my money, readability is the prime
criterion. I work on jobs where code inspection is often the most
cost-effective method of reducing test and integration costs. There is
also a benefit in long term maintenance.

: Larry Kilgallen

Bill Williams
bill.williams@gec-mrc.co.uk