Re: Static constructors inconsistency
On Sunday, 27 April 2014 at 02:06:14 UTC, Ali Çehreli wrote: I don't know whether the inconsistency is a bug but according to documentation, static this inside a module are executed in lexical order: Static constructors within a module are executed in the lexical order in which they appear. http://dlang.org/class.html#StaticConstructor So, if B depends on A then A's static this must appear before B's. Ali Arghh i hate when i make a mistake because i missed something on the docs, mainly when i actually read them. Thanks Ali. Although, yeah, it would be nice if the compiler emitted some kind of warning pointing this (if it's at all possible). What got me confused was indeed the disparity of results from changing small things. Cheers,
Re: Static constructors inconsistency
spec: Although, yeah, it would be nice if the compiler emitted some kind of warning pointing this (if it's at all possible). What got me confused was indeed the disparity of results from changing small things. If you think this can be done and it's useful, then ask for this enhancement request in Bugzilla. Bye, bearophile
Re: Static constructors inconsistency
spec:
Although, yeah, it would be nice if the compiler emitted some
kind of warning pointing this (if it's at all possible). What
got me confused was indeed the disparity of results from
changing small things.
D doesn't like warnings, but it could be an error. This is
minimized code:
struct Foo {
static this() {
Bar b;
int x = b.data[0];
}
}
struct Bar {
static int[] data;
static this() {
data.length++;
}
}
void main() {}
A similar example:
struct Foo {
static this() {
Bar b;
int x = b.data[0];
}
}
struct Bar {
immutable static int[] data;
static this() {
data.length++;
}
}
void main() {}
Is it possible and a good idea to raise a compilation error in
such cases where code tries to use Bar static fields before bar
static this() has run? (But perhaps a more fine-grained error is
needed, that tracks single fields, to allow more flexible code of
mutually initializing constructors).
Bye,
bearophile
Re: Static constructors inconsistency
On Sunday, 27 April 2014 at 13:31:39 UTC, bearophile wrote: Is it possible and a good idea to raise a compilation error in such cases where code tries to use Bar static fields before bar static this() has run? (But perhaps a more fine-grained error is needed, that tracks single fields, to allow more flexible code of mutually initializing constructors). Bye, bearophile I usually try to refrain myself from opinionating on stuff where i lack proper knowledge and i'am still a newbie with D (contrary to you bearophile). Having said this, the current behavior did confused me and it may very well confuse others in the future. I would very much prefer that an error had been thrown, because at that point, i would know immediately that it was me who was doing something wrong.. Cheers,
Re: Static constructors inconsistency
spec: I usually try to refrain myself from opinionating on stuff where i lack proper knowledge and i'am still a newbie with D (contrary to you bearophile). It's not just a matter of experience, when there are many interacting parts it's also a matter of intelligence (and people like Timon are more intelligent than me regardless my experience in D). If no one comment I'll put this in Bugzilla. Bye, bearophile
Re: Static constructors inconsistency
If no one comment I'll put this in Bugzilla. https://issues.dlang.org/show_bug.cgi?id=12667 Bye, bearophile
Static constructors inconsistency
Hello, i'am experiencing some non consistent behavior with static
constructors. I wonder if this is some bug or i just don't know
enough of D (most probably!).. Code example bellow:
//--
module main;
import std.stdio;
class B
{
static this()
{
A a = new A;
int val = a.getValue(A);
}
}
class A {
private static int[string] aa;
static this()
{
aa = [A:1, B:2];
writeln(@ A static ctor!);
}
int getValue(string str)
{
return aa[str];
}
}
void main(string[] args)
{
B B = new B;
}
//--
The text @ A static ctor! never gets printed. The inconsistency
(IMHO) is that if i do any of this:
- Declare class A before B;
- Change the var declared in A from an AA to some other p.e int;
- Comment the line int val = a.getValue(A);
Maybe there are some other points, but at this point i got
confused and decided trying to understand it. Anyway with any of
those changes the text gets printed.
Anyone able to shed some light into this?
Cheers,
Re: Static constructors inconsistency
Btw, i only tested this using v2.065.0 of DMD. Cheers,
Re: Static constructors inconsistency
On 04/26/2014 12:10 PM, spec wrote:
Hello, i'am experiencing some non consistent behavior with static
constructors. I wonder if this is some bug or i just don't know enough
of D (most probably!).. Code example bellow:
//--
module main;
import std.stdio;
class B
{
static this()
{
A a = new A;
int val = a.getValue(A);
}
}
class A {
private static int[string] aa;
static this()
{
aa = [A:1, B:2];
writeln(@ A static ctor!);
}
int getValue(string str)
{
return aa[str];
}
}
void main(string[] args)
{
B B = new B;
}
//--
The text @ A static ctor! never gets printed. The inconsistency (IMHO)
is that if i do any of this:
- Declare class A before B;
- Change the var declared in A from an AA to some other p.e int;
- Comment the line int val = a.getValue(A);
Maybe there are some other points, but at this point i got confused and
decided trying to understand it. Anyway with any of those changes the
text gets printed.
Anyone able to shed some light into this?
Cheers,
I don't know whether the inconsistency is a bug but according to
documentation, static this inside a module are executed in lexical
order: Static constructors within a module are executed in the lexical
order in which they appear.
http://dlang.org/class.html#StaticConstructor
So, if B depends on A then A's static this must appear before B's.
Ali
