Hallo!
I'm just implementing the XML support for PDContainer and now I'm a 
little bit unsure, how the format should look like...
My problem is, that there are associativ containers (like map, set, 
multimap, multiset) which have key-value pairs, and sequences (like 
vector, list, stack, ...) which have only one element.
So some examples (I wrote comments after #):
(a = sequences, b = associativ containers)
1a)
<PDContainer type="h_list">  #container type as attribute
   <list>      # would be a pd list
     <float> 34 </float>   # with a float
     <symbol> afsdf </symbol>  # and a symbol
   </list>
   <float> 423 </float>
   <symbol> sfad </symbol>
   <list>
     <float> -4 </float>
     <symbol> herc </symbol>
   </list>
</PDContainer>
1b) (with abbreviations for list, float and symbol)
<PDContainer type="h_map">
   <key> #1.key
     <l>  #know list is unnecessary
       <f> 34 </f>
       <s> afsdf </s>
     </l>
   </key>
   <value>  #1.value
     <f> 423 </f>
   </value>
   <key>  #2.key
     <s> sfad </s>
   </key>
   <value>  #2.value
     <l>
       <f> -4 </f>
       <s> herc </s>
     </l>
   </value>
</PDContainer>
What I don't like here is, that the keys and values are mixed together, 
so there should be I think an other element tag or something like that ...
2a) with element tag, without list:
<PDContainer type="h_list">
   <element>  # element with 2 entries, so this is a list
     <f> 34 </f>
     <s> afsdf </s>
   </element>
   <element>
     <f> 423 </f>
   </element>
</PDContainer>
2b)
<PDContainer type="h_map">
   <element>
     <key>
       <f> 34 </f>
       <s> afsdf </s>
     </key>
     <value>
       <f> 423 </f>
     </value>
   </element>
</PDContainer>
So I think 2 is clearer than 1, but isn't it too complicated ?
(is there a better word for element ? - because its much to write ...)
Please share your thoughts...
Thanks,
LG
Georg