Re: What's wrong with this syntax?

[rgilbert@polaris.orl.mmc.com (Bob Gilbert)]

John Gluth wrote:
> 
> Howdy,
> 
> Someone on my team asked me if I knew why Rational's Apex doesn't
> seem to like the following excerpts.  I don't see what's wrong with it
> either.
> 
> Some_Limit : Constant := 1024;
> 
> for i in 1..(Some_Limit - 2) loop
> 
> It doesn't seem to want to evaluate the (Some_Limit - 2) expression.
> It seems to me that Some_Limit, a named number is of type Universal
> Integer.
> The literal, 2, should also be of type Universal Integer.
> 
> What are we missing?
> 

Then Ken Garlington replied:

> Here's what DEC Ada V3.2-12 says about your loop:
> 
> "Type {universal_integer} is not allowed for the discrete range of a constrained
> array definition, an iteration rule, or an index of an entry family [LRM 3.6.1(2)].
> Default resolution to the type INTEGER does not apply because one or both expressions
> is not a literal, named number, or attribute; however, the type INTEGER is assumed
> [LRM 3.6.1(2)]."
> 
> Note that both references are to the Ada 83 LRM.
> 
> There are several approaches to fixing the problem; one is
> 
> "for I in Integer'(1) .. (Some_Limit - 2) loop"
> 
> Your code does compile correctly on an Ada 95 compiler (GNAT).

The code compiled without errors using a Tartan C40 compiler (Ver 5.1).
This was true for whether the 9x options switch was off (Ada 83)
or on (some Ada 95 features available).

Curious.

-Bob