🚀 go-pugleaf

Martin> In article <u71z1icf9a.fsf@o2-3.ebi.ac.uk>,
Martin> Philip Lijnzaad  <lijnzaad@ebi.ac.uk> wrote:
>> this is essentially the same as your struct  ...

Martin> No. The essential difference is that you can access a valuetype
Martin> on the language level in a polymorphic way, whereas you have to
Martin> unpack an any in a much more complicated procedure. Please note
Martin> that the subject is "extensible structs" - valuetypes are the
Martin> interoperable version of that, not the any type.

exactly: I am not talking about anys here; you were suggesting to have 

valuetype item{
  public string key;
  public ValueBase value;
}

how does this differ from 

struct item{
  string key;
  any value;
}

apart from the fact that you can extend the valuetype?

Let's not confuse 'extendible structs' (for want of a better term) with hash
tables, even though Perl equates the two (since you can always add something to
your hash^H^H^H^HPerl object by $obj->{more} = q(I'm an extension of $obj)

Martin> valuetype hash{
Martin> private sequence<item> items;
Martin> public ValueBase get(in string key);
Martin> public void set(in string key, in ValueBase value);
Martin> };
>> 
>> ... and this is essentially the same as your interface, with the added
>> inconvenience that the client will have to implement get and set, and that
>> transmitting all the items maybe impossible due to bandwidth  ... 

Martin> No. The essential difference is that all invocations will be local,
Martin> as opposed to being remote - which is an essential difference if
Martin> you have a large number of items.

exactly: transmitting the hashes, if they're big, may not be the right thing
to do. 

I guess I'm confused as to what the original poster wanted: extendability
(offered by vendors-specific stuff such as extendible structs, or by using
valuetype inheritence, or hacks such as XML or anys), OR hash tables. 

                                                                      Philip

-- 
Ban GM foods! Long live the Mesolithicum, pesticides and starvation
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