Hi,
Executing it results in: ** (process:19834): CRITICAL **: thing_set_property: assertion `self != NULL' failed Apparently the c-version of Thing.set_property makes a call to g_return_if_fail, which prints the critical message as thing is null. Shouldn't a programming language, that offers exception handling, throw some kind of null pointer exception?
Two things: 1) AFAIK checking if self != NULL in the beginning of all member functions is a common convention in GObject. Vala follows it. 2) There are no null pointer exceptions - checking every object every time it's used would be too expensive in any sane binary; trapping SIGSEGV could make more sense, and currently I'm developing a library that enables possibility to do this. But it's not beyond proof-of-concept yet, and for some usable shape it needs some time. I'm lazy.
Anyway, changing "int property {get;set;}" to "int property;" even
results in a segmentation fault. It might be discouraged to use a public
property without getters or setters, but valac should generate something
saver than :
Thing* thing;
thing = NULL;
thing->property = 42;
in this case, shouldn't it? My valac version is 0.11.3.
Well, if you have a _property_, it's a setter & getter functions that take object instance as a first argument (self). Following GObject conventions, we just check if self != NULL. But changing it to a _field_ will make a direct access - so it's perfectly sane to segfault here, just as in any other C program where you have a structure pointer == NULL, and try to write to the structure's members. You may be interested in checking how --enable-experimental-non-null - Vala will enforce to never assign null or possibly null value to any reference that's not marked as nullable. best regards,
I am sorry, if this is the hundredth time someone mentions this here, please point me to the according discussion, if this is the case. best regards, Thomas _______________________________________________ vala-list mailing list vala-list gnome org http://mail.gnome.org/mailman/listinfo/vala-list
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