Andreas L Delmelle wrote:
Based on Jörgs statistics, I'd say that the number of children will most likely never reach the level where using direct index-based access (ArrayList) has its benefits over traversing a tree of references (LinkedList).
There may be FOs, specifically fo:flow and fo:table-body, which may have hundreds of children in real documents. If the FOs use access functions for the children, even for adding, each FO can implement a mechanism which suites its purposes best. In particular, page masters and tables can store the regions in typed fields, FOs which don't have children can get rid of the field completely. I'm not sure whether the layout engine places any restrictions on the access to FO children. Is it possible that access is not random? J.Pietschmann