SQL expr variants are lost when converting from Rust to Elixir

[hexedpackets]

For example, the query select a from foo where a > any(b) gets parsed by sqlparser into:

[Query(Query { with: None, body: Select(Select { distinct: None, top: None, projection: [UnnamedExpr(Identifier(Ident { value: "a", quote_style: None }))], into: None, from: [TableWithJoins { relation: Table { name: ObjectName([Ident { value: "foo", quote_style: None }]), alias: None, args: None, with_hints: [] }, joins: [] }], lateral_views: [], selection: Some(BinaryOp { left: Identifier(Ident { value: "a", quote_style: None }), op: Gt, right: AnyOp(Identifier(Ident { value: "b", quote_style: None })) }), group_by: [], cluster_by: [], distribute_by: [], sort_by: [], having: None, named_window: [], qualify: None }), order_by: [], limit: None, offset: None, fetch: None, locks: [] })]

Note the AnyOp inside the selection's BinaryOp struct. Convering this with serde_rustler strips this variant:

[
   %JumpWire.Proxy.SQL.Statement.Query{
     locks: [],
     fetch: nil,
     offset: nil,
     limit: nil,
     order_by: [],
     body: %JumpWire.Proxy.SQL.Statement.Select{
       qualify: nil,
       named_window: [],
       having: nil,
       sort_by: [],
       distribute_by: [],
       cluster_by: [],
       group_by: [],
       selection: %JumpWire.Proxy.SQL.Statement.BinaryOp{
         right: %JumpWire.Proxy.SQL.Statement.Ident{
           quote_style: nil,
           value: "b"
         },
         op: :gt,
         left: %JumpWire.Proxy.SQL.Statement.Ident{quote_style: nil, value: "a"}
       },
       lateral_views: [],
       from: [
         %JumpWire.Proxy.SQL.Statement.TableWithJoins{
           joins: [],
           relation: %JumpWire.Proxy.SQL.Statement.Table{
             with_hints: [],
             args: nil,
             alias: nil,
             name: [
               %JumpWire.Proxy.SQL.Statement.Ident{
                 quote_style: nil,
                 value: "foo"
               }
             ]
           }
         }
       ],
       into: nil,
       projection: [
         %JumpWire.Proxy.SQL.Statement.Ident{quote_style: nil, value: "a"}
       ],
       top: nil,
       distinct: nil
     },
     with: nil
   }
 ]

This is probably a bug with serde_rustler that needs to be fixed in our fork.