[erlang-questions] Are nested records copied?

Bryan Hughes <>
Sat Jun 1 17:55:32 CEST 2013


Thanks Bob - that is what I was thinking/hoping.

On 6/1/13 8:50 AM, Bob Ippolito wrote:
> It's not copied in this case, nested records aren't flattened or 
> anything like that. Records are just tuples after all.
>
> On Saturday, June 1, 2013, Bryan Hughes wrote:
>
>     Howdy!
>
>     I am working on section of code that will be dealing with a large
>     number of records in a relatively tight loop and have a question
>     in how Erlang constructs a nested record.
>
>     If I define a person and manager record:
>
>     1> rd(person, {name, age}).
>     person
>     2> rd(manager, {person, dept}).
>     manager
>
>     Then create a person record:
>
>     3> P = #person{name = bryan, age = 45}.
>     #person{name = bryan,age = 45}
>
>     And then a manager record:
>
>     4> M = #manager{person = P, dept = foo}.
>     #manager{person = #person{name = bryan,age = 45},dept = foo}
>
>     When the manager record is created, is the nested person record P
>     referenced by the manager record M, or is it copied?
>
>     Thanks,
>     Bryan
>
>     -- 
>
>     Bryan Hughes
>     *Go Factory*
>     http://www.go-factory.net
>
>     /"Internet Class, Enterprise Grade"/
>
>

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