Hi! The spec... http://svn.openehr.org/specification/TAGS/Release-1.0.1/publishing/architecture/rm/common_im.pdf ...indicates that an ITEM_TREE should contain it's items as an attribute "items: LIST<ITEM> Physical representation of the tree."
The function as_hierarchy reads... "as_hierarchy: CLUSTER Generate a CEN EN13606-compatible hierarchy, which is the same as the tree's physical representation." Then in another part of the spec: "4.2.4 ITEM_TREE Data of an ITEM_TREE instance are simply replicated as is to produce the correct EN13606 hierarchical form" Then the instance structure examples in 4.4.4. seems to have placed the items as a list directly under the ITEM_TREE It's a bit confusing and some further documentation (at least of as_hierarchy) might be good for pedagogical reasons. Is the "as_hierarchy" to be interpreted as something like create and return a new CLUSTER object where the cluster root node takes its attributes like name etc from the ITEM_TREE object and copy the "items" list from the ITEM_TREE to the new CLUSTER? Any thoughts about what kind of copying should be done in an implementation? Creating new identical "item" objects or just point to the existing ones? Is there any other important difference between CLUSTER and ITEM_TREE than the extra functions has_element_path, element_at_path and as_hierarchy (and the class hierarchy)? Can anybody elaborate a bit on this? Maybe I've just been sitting too long in front of the computer, time to go... Best regards, Erik Sundvall http://www.imt.liu.se/~erisu/
