Struct definition : self-referencing structs and struct inheritance.

[Martin Ritchie <ri...@apache.org>]

Hi I'm investigating the possibility of using Thrift however, I
currently have the need for two things that I don't think Thrift
currently supports: self referencing structs and struct inheritance.

The type of data I'm trying to serialise is a tree so Type A contains
a list of A.
However A also has a tree of sub-types A->B->C, A->D  etc.

Ideally I'd like to represent this in thrift as something like:

struct A
{
 1: i32 id,
 2: list<A> children
}

struct B extends A
{
 1:i32 extraField
}

Apologies if this has previously been discussed. Is this something
that was ruled out? Is anyone interested and/or working on this
already?

Regards

Martin

-- 
Martin Ritchie

Re: Struct definition : self-referencing structs and struct inheritance.

[Bryan Duxbury <br...@rapleaf.com>]

The short answer is that many people would like this feature, but we've
decided against it due to the resulting complexity in some languages like
C++.

To approximate the first struct, your best bet is to move the children thing
up a level:

struct A {
  1: i32 id
}

struct AWithChildren {
  1: A a;
  2: list<A> children;
}

And instead of inheritance, you can always fall back on composition.

-Bryan

On Thu, Nov 18, 2010 at 7:25 PM, Martin Ritchie <ri...@apache.org> wrote:

> Hi I'm investigating the possibility of using Thrift however, I
> currently have the need for two things that I don't think Thrift
> currently supports: self referencing structs and struct inheritance.
>
> The type of data I'm trying to serialise is a tree so Type A contains
> a list of A.
> However A also has a tree of sub-types A->B->C, A->D  etc.
>
> Ideally I'd like to represent this in thrift as something like:
>
> struct A
> {
>  1: i32 id,
>  2: list<A> children
> }
>
> struct B extends A
> {
>  1:i32 extraField
> }
>
> Apologies if this has previously been discussed. Is this something
> that was ruled out? Is anyone interested and/or working on this
> already?
>
> Regards
>
> Martin
>
> --
> Martin Ritchie
>