Re: Required Metrics

["Robert I. Eachus" <rieachus@earthlink.net>]

Robert A Duff wrote:
  
> That test is clearly wrong.  I'm surprised nobody has challenged it.
> There is no requirement that a compiler impose a maximum line-length
> limit, and there never has been.
 
> I guess it's easier to make your compiler pass a test than it is to go
> through the challenge process.  Sigh.

  If the test is still in the suite, it definitely should be
challenged.  The Ada 95 rules explicitly allow the maximum identifier
length to be different from the maximum line length.

  However, in the early days of Ada 83 validation--around ACVC 1.4--you
were faced with
an impossible Catch-22.  You could argue that the test had to be
modified for your implementation, but you still had to demonstrate
somehow, that an identifier of maximum
length was accepted, and an identifier of maximum length + 1 was either
rejected by the
compiler, or impossible to create in a file.

  And yes, we took the easy way out on the compiler for the Honeywell
DPS6.  The "real" maximum line length for {normal} text files was 255
characters.  It was MUCH easier to set the maximum Ada source file line
length to 253 and pass the ACVC test as written, than to try to
demonstrate that we couldn't create a non-standard file containing an
identifier longer than the maximum line length.  (The choice of 253 was
for consistancy with Ada Text_IO files, where we needed a couple extra
characters for new page and end of file makers.)