Re: Division by zero

[Jeffrey Carter <spam@spam.com>]

Robert A Duff wrote:

> It's hard to come up with legitimate examples of that.
> As others have pointed out, "raise C_E" is usually the
> best way to raise C_E.

I agree, though they do exist.

> Here's an example that agrees with your point:

Good example.

> (In fact, if Gizmos is static, then the above *is* illegal in Ada 95,
> but not Ada 83.)

Are you sure? In my examples, both operands are static.

> The rules about static expressions do not apply to user-defined
> operators, which can do anything you like.

This is an area of Ada 95 that sometimes bites me because I got used to 
the Ada-83 rules. In Ada 83, any static universal expression was 
evaluated at compile time. In Ada 95, if the context of the expression 
has a type, the operator for that type must be invoked; since that 
operator may be redefined, the expression must be evaluated at run time.

> Careful!  That looks like an infinite recursion.

Well spotted. I could admit that I didn't pay attention to that branch 
because it would never be invoked, but instead I'll claim that infinite 
recursion was the desired behavior if you try to divide by anything 
other than zero.

-- 
Jeff Carter
"Blessed are they who convert their neighbors'
oxen, for they shall inhibit their girth."
Monty Python's Life of Brian
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