Re: [Vala] How to initialize static field

[Pavel Stupnikov <dp dpointer org>]

> > I want to create some static fields. Int field works ok, but HashMap
> > remains null even after initialization... What i did wrong?
> >      
> You didn't run the initialization. The static constructor only runs when
> the corresponding metaobject is requested for the first time. It is only
> requested when you create instance, call "class" methods, access "class"
> members or use typeof on the type. It is however NOT requested when you
> use "static" methods and members.
>
>    
Thanks! I couldn't find anything about such behaviour in documentation :(

But i still don't understand how to initialize it properly:
> > public static class Foo: Object {
> >       public static HashMap<string, int>  bar = new HashMap<string, int>();
> >      
> This is only executed when you obtain the class object.
>
> If the member was a class one rather than static one, i.e.
>
>         public class HashMap<string, int>  bar = new HashMap<string, int>();
>
> the initialization would be enforced when accessing it (at the cost of the
> access being slightly slower).
>    

public static class Foo: Object {
public class HashMap<string, int> bar = new HashMap<string, int>();
public static int a = 5;
}

void main () {
stdout.printf("a = %d\n",Foo.a);
stdout.printf("bar: %s\n",(Foo.bar==null?"null":"ok"));
}

Failed to compile:

$ valac --pkg=gee-1.0 t1.vala --pkg=vala-1.0

** (valac:29753): CRITICAL **: vala_ccode_function_call_add_argument: 
assertion `expr != NULL' failed
/home/pavels/Projects/vala_test/t1/t1.vala.c: In function ‘_main’:
/home/pavels/Projects/vala_test/t1/t1.vala.c:94: error: expected 
expression before ‘)’ token
error: cc exited with status 256
Compilation failed: 1 error(s), 0 warning(s)

> > void main () {
> >      
> To enforce initialization of static members of Foo, you can try putting
>         typeof(Foo);
> here.
>
>    

Didn't help either:

using Gee;

public static class Foo: Object {
public static HashMap<string, int> bar = new HashMap<string, int>();
public static int a = 5;
}

void main () {
typeof(Foo);
stdout.printf("a = %d\n",Foo.a);
stdout.printf("bar: %s\n",(Foo.bar==null?"null":"ok"));
}

prints

a = 5
bar: null