digitalmars.D.bugs - foreach on aggregate class in some delegate litterals
- simon hudon (64/64) Jul 16 2006 Hi everyone,
- Thomas Kuehne (13/77) Sep 14 2006 -----BEGIN PGP SIGNED MESSAGE-----
Hi everyone,
I caught quite a bizarre bug on dmd v0.162 : if I use a foreach to iterate
through an aggreate class instance in a litteral delegate between brackets, like
this :
=====================================================
// some container
class Container {
int opApply (int delegate (inout int) dg) {
int i;
dg(i);
return 0;
}
}
void main () {
// a is assigned a delegate specified by a litteral
auto a = ( {
foreach (i ; new Container)
writefln(i);
});
}
=====================================================
the compiler crashes saying :
Assertion failure: 'type || init' on line 440 in file 'declaration.c'
abnormal program termination
But if I make one of two possible changes, it compiles and runs without problem.
First, if I want to iterate through a static or a dynamic array (an associative
array won't work, though), it compiles and run perfectly. Here's an example :
=====================================================
void main () {
int[] b;
// a is assigned a delegate specified by a litteral
auto a = ( {
foreach (i ; b)
writefln(i);
});
}
=====================================================
A perfect work around (in appearance at least, I just spent three hours on that
problem so I don't pretend to have tested everything) is to tell the compiler
explicitly that the expression in the right side of the assignment is a
delegate, like this :
=====================================================
// some container
class Container {
int opApply (int delegate (inout int) dg) {
int i;
dg(i);
return 0;
}
}
void main () {
// a is assigned a delegate specified by a litteral
auto a = ( delegate int(){
foreach (i ; b)
writefln(i);
} );
}
=====================================================
It seems that this is not a really bad bug since you can get the work done
simply by adding the type of the delegate, but I think the syntax without those
keywords should work whatever is in the delegate.
Thanks for your attention.
Cheers
Simon Hudon
Jul 16 2006
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Hash: SHA1
simon hudon schrieb am 2006-07-17:
Hi everyone,
I caught quite a bizarre bug on dmd v0.162 : if I use a foreach to iterate
through an aggreate class instance in a litteral delegate between brackets,
like
this :
=====================================================
// some container
class Container {
int opApply (int delegate (inout int) dg) {
int i;
dg(i);
return 0;
}
}
void main () {
// a is assigned a delegate specified by a litteral
auto a = ( {
foreach (i ; new Container)
writefln(i);
});
}
=====================================================
the compiler crashes saying :
Assertion failure: 'type || init' on line 440 in file 'declaration.c'
abnormal program termination
But if I make one of two possible changes, it compiles and runs without
problem.
First, if I want to iterate through a static or a dynamic array (an associative
array won't work, though), it compiles and run perfectly. Here's an example :
=====================================================
void main () {
int[] b;
// a is assigned a delegate specified by a litteral
auto a = ( {
foreach (i ; b)
writefln(i);
});
}
=====================================================
A perfect work around (in appearance at least, I just spent three hours on that
problem so I don't pretend to have tested everything) is to tell the compiler
explicitly that the expression in the right side of the assignment is a
delegate, like this :
=====================================================
// some container
class Container {
int opApply (int delegate (inout int) dg) {
int i;
dg(i);
return 0;
}
}
void main () {
// a is assigned a delegate specified by a litteral
auto a = ( delegate int(){
foreach (i ; b)
writefln(i);
} );
}
=====================================================
It seems that this is not a really bad bug since you can get the work done
simply by adding the type of the delegate, but I think the syntax without those
keywords should work whatever is in the delegate.
Thanks for your attention.
Cheers
Simon Hudon
Added to DStress as
http://dstress.kuehne.cn/b/bug_declaration_440_A.d
http://dstress.kuehne.cn/b/bug_declaration_440_B.d
http://dstress.kuehne.cn/b/bug_declaration_440_C.d
Thomas
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Sep 14 2006








Thomas Kuehne <thomas-dloop kuehne.cn>