On 14.04.2013 21:31, Jonas Kulla wrote: > 2013/4/14 Alexander Krivács Schrøder <alexsch...@gmail.com > <mailto:alexsch...@gmail.com>> > > Hi. > > I'm trying to use Glib.TimeVal with its from_iso8601() > initializer, but > I can't get the generated C code not to contain a call to > g_get_current_time() first. At first, I tried this Vala code: > > string iso8601_date = "1999-05-31T11:20:00"; > TimeVal time_val; > time_val.from_iso8601(iso8601_date); > > but that makes the compiler complain: > > error: use of possibly unassigned local variable `time_val' > > So then I tried this code: > > string iso8601_date = "1999-05-31T11:20:00"; > TimeVal time_val = TimeVal(); > time_val.from_iso8601(iso8601_date); > > but that makes the compiler output the following code: > > g_get_current_time (&time_val); > g_time_val_from_iso8601 (iso8601_date, &time_val); > > What do I do to make it not call g_get_current_time()? I know it's > probably minimal, but it's still wasted CPU cycles and extraneous code > to compile and whatnot, and I want the option to leave it out if > at all > possible. If it isn't possible, a way to make it possible should be > considered to be implemented. > > Regards, > Alexander K. Schrøder > > > _______________________________________________ > vala-list mailing list > vala-list@gnome.org <mailto:vala-list@gnome.org> > https://mail.gnome.org/mailman/listinfo/vala-list > > > Hi, > > GTimeVal seems a little bit problematic. Ideally, you would want to > declare > the "from_iso8601" method as a named constructor to circumvent the default > one (which results in the g_get_current_time), and from a small test I > just did > this works out fine Vala wise. The only problem I see is that this > call returns > a boolean indicating whether the conversion was successful, which would be > lost without any way to find out the result. I guess the way it should > really be > done is to have the default constructor just initialize the struct to > zero and have > the "get_current_time" as a separate method, but for that additional > glib code > would have to exist. > > I think your best trade off would be to go with your first suggestion > and ignore > the valac warning. But why is circumventing the get_current_time call so > important to you? Are you running this code in a tight loop? > > Jonas
I would go with my first suggestion, except it's an error and not a warning, so it doesn't compile at all. No, I don't particularly need to circumvent the call. This is mostly a theoretical desire to be able to accomplish in Vala the same thing I could accomplish in C. Were I to write the code in C, I could just leave out the call, so why shouldn't I be able to accomplish the same goal in Vala? Or, more appropriately, why should Vala HAVE to call g_get_current_time just for me to get a hold of a TimeVal struct? For the most part, Vala produces code about as efficient as manual C code can be written, which is one of the main reasons why I like Vala so much, but when it decides to force me to throw in a function call that I don't need, that feeling of efficiency falls a little short. So yeah... mostly intellectual curiosity, really. Regards, Alexander K. Schrøder
signature.asc
Description: OpenPGP digital signature
_______________________________________________ vala-list mailing list vala-list@gnome.org https://mail.gnome.org/mailman/listinfo/vala-list
