Re: Division by zero

["David C. Hoos, Sr." <david.c.hoos.sr@ada95.com>]

The reason for the difference is that because both terms of line 1
are known at compile time, the computation is performed at compile
time, and thus raises the exception.

Since the numerator of line 2 is a variable, the compiler does not
attempt any computation, and thus does not signal an error.

Constraint_Error will be raised at runtime.

----- Original Message ----- 
From: "Lurker" <nowhere@nothing.com>
Newsgroups: comp.lang.ada
To: <comp.lang.ada@ada-france.org>
Sent: June 11, 2005 4:03 PM
Subject: Division by zero


> Hi,
> 
> I'm curios about the problem which I discovered by accident.
> The code below is of course very much reduced to show
> the it:
> 
> function x(a: integer) return integer is
> 
> some_constant: constant := 0;
> 
> begin
> 
> -- return 1/some_constant; -- line 1
> 
> -- return a/some_constant; -- line 2
> 
> end;
> 
> 
> 
> If line 1 is uncommented compiler (Gnat 3.15 for Widows)
> 
> produces the expected error about division by zero.
> 
> If line 2 is uncommented it passes compilation with no problem.
> 
> Surely that's not right? Or did I miss something?
> 
> 
> 
> 
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