Re: C++ vs. Ada -- Is Ada loosing?

[agate!spool.mu.edu!yale.edu!qt.cs.utexas.edu!cs.utexas.edu!milano!teenwol f.mcc.com!srogers@ucbvax.Berkeley.EDU (Steve Rogers)]

In article <MMEYER.92Dec31114831@m2.dseg.ti.com> mmeyer@m2.dseg.ti.com (Mark Me
yer) writes:
>
>	I'm new to this group, basically because I'm new to Ada.
>Even so, I just have to comment on this:
>
>In article <1992Dec21.161105.9344@mcc.com> srogers@teenwolf.mcc.com (Steve Rog
ers) writes:
>> The edition I am looking at is the 3rd edition.
>
>	Are you sure?  I'm looking at the 3rd Edition myself.  When
>was your copy printed?  This book seems to go through a reprint twice
>every year, and mine's from 1990.  I only ask because both your
>examples of errors seem to be in error themselves, at least as far as
>my copy is concerned.
>
>> Two examples: The FRAME program on page 325 violates LRM 9.1.4 - the
>> type of the task cannot be used as a typemark within the task itself.
>> It's easy to see what the program means, but it doesn't comple. 
>
>	No, it doesn't violate 9.1.4.  I could tell that by
>inspection.  I was even able to compile it (after removing references
>to the FRAME package - I don't know how to get our compiler to build a
>library and someone else has the manual).  Nowhere in the task body of
>FILTER does anyone try to use FILTER as a type.  In fact, on p. 327
>Barnes specifically states, "(The use of the function MAKE_FILTER is
>necessary to overcome a rule that in the body of a task type its name
>refers to the current task and not the type.)"

The date on my copy is 1989.  The FILTER task references itself on page 326.
I suppose the error was found and corrected in later editions.

>> There is a task example on page 311 that has nested accepts for the
>> same entry which violates LRM 9.5(8).  Again, its clear what the
>> program intends, but it has been simplified in a way that keeps it
>> from compiling.
>
>	I was able to compile this program too.  In my copy of the
>book, the accepts are not nested.  Do you have the 3rd Edition,
>printed in 1990?  Maybe your book was printed earlier?

Whoops!  I misread this one.  

The correction of the FRAME error answers the larger question of whether
or not the errors were intentionally included to make the examples
"easier" to understand.  It appears that this is NOT the case.

-- 
| Steven Rogers  MCC/ESL  3500 West Balcones Drive
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