digitalmars.D.bugs - foreach on aggregate class in some delegate litterals
- simon hudon <simon_member pathlink.com> Jul 16 2006
- Thomas Kuehne <thomas-dloop kuehne.cn> Sep 14 2006
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
-----BEGIN PGP SIGNED MESSAGE----- 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 -----BEGIN PGP SIGNATURE----- iD8DBQFFCQ3ELK5blCcjpWoRArbUAJ4vfguxh8+XjmEyjOlgDmTLyxTP7gCgiIcK GJBmQZmG/E0X+aWGyCWNhP4= =fYbQ -----END PGP SIGNATURE-----
Sep 14 2006








Thomas Kuehne <thomas-dloop kuehne.cn>