Samuele Pedroni wrote:

Records are really like lltypesystem Structs, although because some of their code was copied from Instance, they may give the impression that you can add fields after the fact, but that should not be done, it breaks the fact that they are supposed to compare by structure.

If you are needing that you need some other approach or introduce some kind of forward definition.

_add_fields should really disappear from Record.

ok, so it's my fault, but it don't solve my original problem. The problem is that TestCliTuple.test_inst_tuple_add_getitem in test_rpython.py used to fail because the IL code contained two copies of the same Record. After a bit of investigation I discovered that the reason was because I got two Records that compare equal but have different hashes; again, the problem was that the __cached_hash was different from the real one. Then I tried to reproduce the bug, and so I wrote the failing test, thinking that using _add_fields was fine. But after your comment I've understood that this is not the point, because Record._add_fields is called only in its __init__. For now the problem is worked-around in database.py (the lines marked with "XXX: temporary hack"), but the bug is still here: any idea of why I get two equal Records with different hashes? ciao Anto

Samuele Pedroni wrote:

Records are really like lltypesystem Structs, although because some of their code was copied from Instance, they may give the impression that you can add fields after the fact, but that should not be done, it breaks the fact that they are supposed to compare by structure.

If you are needing that you need some other approach or introduce some kind of forward definition.

_add_fields should really disappear from Record.

ok, so it's my fault, but it don't solve my original problem. The problem is that TestCliTuple.test_inst_tuple_add_getitem in test_rpython.py used to fail because the IL code contained two copies of the same Record. After a bit of investigation I discovered that the reason was because I got two Records that compare equal but have different hashes; again, the problem was that the __cached_hash was different from the real one. Then I tried to reproduce the bug, and so I wrote the failing test, thinking that using _add_fields was fine. But after your comment I've understood that this is not the point, because Record._add_fields is called only in its __init__. For now the problem is worked-around in database.py (the lines marked with "XXX: temporary hack"), but the bug is still here: any idea of why I get two equal Records with different hashes? ciao Anto