Hi Kengo,
I don't think this is a bug, as records are designed to "act as
transparent carriers for immutable data". A record having an array-typed
component is far from being immutable because everyone can change the
array contents. So you probably shouldn't opt for records for such use
cases, since you would loose the semantic benefits of records.
But if you need deeper hashing and comparison over array-typed
components of records, as you are probably expecting in your example,
you have to override the record hashCode() and equals() yourself. But
then (http://openjdk.java.net/jeps/395):
"Any explicit implementation of accessors or the equals or hashCode
methods should be careful to preserve the semantic invariants of the
record class."
Greetings
Raffaello
Hello there,
I'm Kengo TODA, an engineer learning about the Record feature.
Today I found a nonintentional behavior, and it seems that the bug database
has no info about it.
Let me ask here to confirm it's by-design or not. If it's a bug, I want to
try to send a patch to OpenJDK.
Here is the code reproducing the nonintentional behavior:
https://gist.github.com/KengoTODA/4d7ef6a5226d347ad9385241fee6bc63
In short, the ObjectMethods class in OpenJDK v16 generates code
that invokes the fields' method, even when the field is an array.
Please help me to understand this behavior, or
make an entry in the bug database to propose a patch.
Thanks in advance! :)
***
Kengo TODA
skypencil at gmail.com
