| Subject | Re: [firebird-support] Is this a bug of Firebird? |
|---|---|
| Author | Tim Ward |
| Post date | 2017-02-09T09:30:06Z |
x = a;
x = b;
where the compiler is expected to know that neither a not the first assignment have any side effects other than the assignment (and where the expression b doesn't depend on the value of x)(and where x isn't volatile, ect ect).
A compiler *could* detect and warn about such things (ie it's not forbidden by the laws of mathematics) but I don't think I know of any that do. And as there are good reasons for deliberately wanting to do the above it could only be a warning, not an error.
On 08/02/2017 23:36, 'Walter R. Ojeda Valiente' sistemas2000profesional@... [firebird-support] wrote:
The error is of the programmer, I agree with you, but to repeat the name of a variable without the Firebird showing any message of error is, at least for me, a bug.
To have 2 or more variables with the same name after the INTO clause is useless. The compiler can be smart enough to detect such thing.
Or not?
Greetings.
Walter.
On Wed, Feb 8, 2017 at 2:36 PM, 'Leyne, Sean' Sean@... [firebird-support] <firebird-support@yahoogroups.com> wrote:
> Yes, but I can not know the value of the column X.ALU_NOMBRE
>
> And the idea, of course, is know that value, that's why it appears in the FOR
> SELECT. If not, I can do nothing with X.ALU_NOMBRE
You are asking for the system to evaluate the *intent* of logic.
That is completely outside the purview of any application environment that I know.
The only thing that a system can check/enforce is the correctness of the code, not to check whether the developer has 2 brain cells.
Sean
-- Tim Ward