Re: aedis review starts today

From: Jakob Lövhall (lovhall_at_[hidden])
Date: 2023-01-21 18:04:44

making the error text available is not only logging. it can be passed on to a user in interactive sessions giving the user (human) ability to act on it right away.
I wouldn't call that "only useful for logging" even though I guess it is logging in some sense.

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------- Original Message -------
On Saturday, January 21st, 2023 at 18:47, Marcelo Zimbres Silva via Boost <boost_at_[hidden]> wrote:

> On Sat, 21 Jan 2023 at 18:28, Ruben Perez rubenperez038_at_[hidden] wrote:
> 
> > > I know Boost.MySql invented error_info to deal with this problem. I
> > > did not adopt it because
> > > 
> > > * Deviates the completion signature from well established practice of
> > > having error_code as first parameter f(erro_code ec, ...) or
> > > This is not true. error_info (now server_diagnostics) are never
> > > part of the completion handler signature, but populated by lvalue reference.
> > 
> > > * Requires additional parameters to the completion e.g. f(error_code
> > > ec, error_info ei, ...)
> > > Again, this is not true.
> > 
> > > * Raises question about who allocates the string.
> > > The string is allocated as any other data passed by lvalue reference.
> > 
> > I'm not saying error_info (aka server_diagnostics) is the solution,
> > but none of these arguments are true.
> 
> 
> Indeed, it is passed to the initiating function
> https://anarthal.github.io/mysql/mysql/ref/boost__mysql__connection/async_query/overload2.html
> 
> template<class CompletionToken>
> 
> auto async_query(
> boost::string_view query_string,
> error_info& output_info,
> CompletionToken&& token);
> 
> Which is similar to what I am proposing in the github issue I point
> you at. Sorry for the confusion, I have discussed extensively with
> others why not pass in the completion handler and though I had seen
> this first in Boost.MySql when I wrote a review.
> 
> > > * The error information is also only useful for logging and the user
> > > can't react to it so why not log it right away.
> > > I'm not getting this. How can I log something if I can't access it?
> 
> 
> A high-level library might decide not to pass this information to the
> user but log it right away. Users will react to error_code and not to
> error_info which AFAICS is only used for logging.
> 
> Regards,
> Marcelo
> 
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