Re: ALTER, ASSIGN and labels-as-values (was: Unicode in strings)

John Levine wrote:

According to Stephen Fuld <SFuld@alumni.cmu.edu.invalid>:

As I said before, you could easily scan the source code and find all
the ALTER statements ...

 
Hm, I'm guessing you've never dropped a box containing 2000 source
cards.

I have (remember using a marker to put a diagonal line across the top
of the deck to make it easier to spot an out of order card?  :-(.  But
that isn't the point.  When I said scan, I was referring to the paper
listings that, in the day, were easily available.

COBOL dates from about 1960, while online text editors, as opposed to
coding forms and keypunches, didn't become common until the 1970s and
in some places even later.

Sure, but paper listings were available long before online text
editors.  That is what I used, circa early 1970s.

 

It really mattered that it was obvious that a Fortran assigned GOTO
could go anywhere, but in COBOL an altered GOTO looked just like an
unaltered one.

While I suppose you could code a paragraph with only a GOTO statement,
(required syntax for the ALTERable GOTO), I see no reason to, so while
the GOTO statement itself was syntactically identical to a non
ALTERable GOTO, the fact that it was in a paragraph by itself made it
unique in the source code listing.

 
Dunno why COBOL didn't have label variables instead.  It wouldn't
have been any harder.

I don't know either.


Note that I am absolutely not arguing that ALTER GOTO was a good idea.
I am just responding to John's assertion that putting it in the
language was "irresponsible", because a programmer could "hide"
malicious code.

While I suppose any feature that makes code harder to comprehend makes
it easier to hide malicious code, John presented no evidence that
anyone ever did this, and I suspect that "easier to hide malicious
code" was not among the most important reasons for the feature's
deprecation.



--
 - Stephen Fuld
(e-mail address disguised to prevent spam)