default_filname = "project/documentation.fodt" : string;

/* require ptrvalid */
/* local scope doc ptr */

XmlNode = type {
        tag: string; 
        attrs: [string]; 
        content: string}.
        
Tree = type(Leaf) Tree [Leaf; [Tree(Leaf)]];

XmlTree = Tree(XmlNode);


children = function: (tree: xmlNodePtr)->XmlTree
{
    childrenRaw = tree[xmlChildrenNode]: [xmlNodePtr], linkedlist(next, null);
    
    map (childrenRaw->childRaw: xmlNodePtr) {
      Tree[childRaw[name] children(childRaw)]
    }
}


document = function: (filename: string)->XmlTree
{
  docRaw = xmlParseFile(docname.c_str()) : xmlDocPtr;
  nodeRaw= xmlDocGetRootElement(docRaw) : xmlNodePtr;
  
  Tree [nodeRaw[name] children(nodeRaw));
}


query = function: (tree: XmlTree) [string, string]
{
    children :  context(children) = 
      case default
        []
      
      case (tree[0]: NeedChildren(childrenFilters), ApplyTransform(transFilters))
      {
        loop fold (tree[1]->child: Tree(Leaf) | childrenFilters; []->accum).
            {accum  + traverse(child): cases(transFilters) };
      }

    node = 
      case (node.tag == "style:style"; class = node[attrs, "style:name"]; exists(class, ParaKnownClasses))
      {
        [class, node[attrs, "style:display-name"]];
      }
      
      case default
        [] ;
      
      node + children;
}


test = function: ()->num
{
    data = query(document(default_filename)): [string, string];
    
    exists(data, "pgess1").
}