Re: Language Lawyers help on rep_specs

[stt@spock.camb.inmet.com (Tucker Taft)]

In article <3ebo8f$jlo@theopolis.orl.mmc.com>,
Theodore E. Dennison <dennison@escmail.mmc.orl.com> wrote:
>jeffe@hathor.CSS.GOV (Jeff Etrick) wrote:

>> Dear Language Lawyers,
>> 
>(stuff deleted)
>> The LRM references are saying that my type Nuclear_Date_Times may not be
>> used in a record represenation clause due to the fact it is not a simple
>> static expression. Talking to the vendor about 
>> this issue I was told that the
>> INTEGER conversion is a function and functions are not allowed in simple
>> static expressions.
>> 
>> Looking at 4.9(6) "a function_call whose function_name .........."
>> tells me that static functions are allowed.
>> 
>> My vendor insists that my program violates the LRM, could you please
>> enlighten me on this. Which vendor is executing this program correctly?
>
>(code deleted)
>>   type Dates is new Full_Integer range -1 .. 56_613;
>(code deleted)
>>   type Nuclear_Date_Times is new Full_Integer
>>     range (INTEGER (Dates'first) - 1) * MINUTES_IN_DAY
>>                 .. (INTEGER (Dates'last) * MINUTES_IN_DAY) - 1;
>
>Your vendor is partly correct; 

No, your vendor is completely incorrect ;-).  "Integer()" is not a function
call, it is an explicit conversion.  Unlike Ada 83, explicit
conversions can be part of a static expression in Ada 95.  I suspect
they have not yet fully updated their compiler to Ada 95 rules.

> ...
>Therefore "INTEGER (Dates'first)" and "INTEGER (Dates'last)" are not 
>static.

Integer(Dates'First) and Integer(Dates'Last) are both static in Ada 95.

> ...
>T.E.D.

S. Tucker Taft   stt@inmet.com
Ada 9X Mapping/Revision Team
Intermetrics, Inc.
Cambridge, MA  02138