package treeops import ( "fmt" "github.com/elliotchance/orderedmap" ) type dataTreeNavigator struct { leafTraverser LeafTraverser operatorHandlers map[OperationType]OperatorHandler } type NavigationPrefs struct { FollowAlias bool } type DataTreeNavigator interface { GetMatchingNodes(matchingNodes []*CandidateNode, pathNode *PathTreeNode) ([]*CandidateNode, error) } func NewDataTreeNavigator(navigationPrefs NavigationPrefs) DataTreeNavigator { leafTraverser := NewLeafTraverser(navigationPrefs) operatorHandlers := make(map[OperationType]OperatorHandler) operatorHandlers[Traverse] = TraverseOperator operatorHandlers[Equals] = EqualsOperator operatorHandlers[Or] = UnionOperator operatorHandlers[And] = IntersectionOperator operatorHandlers[Assign] = AssignOperator operatorHandlers[DeleteChild] = DeleteChildOperator return &dataTreeNavigator{leafTraverser, operatorHandlers} } func (d *dataTreeNavigator) traverse(matchMap *orderedmap.OrderedMap, pathNode *PathElement) (*orderedmap.OrderedMap, error) { log.Debugf("-- Traversing") var matchingNodeMap = orderedmap.NewOrderedMap() var newNodes []*CandidateNode var err error for el := matchMap.Front(); el != nil; el = el.Next() { newNodes, err = d.leafTraverser.Traverse(el.Value.(*CandidateNode), pathNode) if err != nil { return nil, err } for _, n := range newNodes { matchingNodeMap.Set(n.getKey(), n) } } return matchingNodeMap, nil } func (d *dataTreeNavigator) GetMatchingNodes(matchingNodes []*CandidateNode, pathNode *PathTreeNode) ([]*CandidateNode, error) { var matchingNodeMap = orderedmap.NewOrderedMap() for _, n := range matchingNodes { matchingNodeMap.Set(n.getKey(), n) } matchedNodes, err := d.getMatchingNodes(matchingNodeMap, pathNode) if err != nil { return nil, err } values := make([]*CandidateNode, 0, matchedNodes.Len()) for el := matchedNodes.Front(); el != nil; el = el.Next() { values = append(values, el.Value.(*CandidateNode)) } return values, nil } func (d *dataTreeNavigator) getMatchingNodes(matchingNodes *orderedmap.OrderedMap, pathNode *PathTreeNode) (*orderedmap.OrderedMap, error) { log.Debugf("Processing Path: %v", pathNode.PathElement.toString()) if pathNode.PathElement.PathElementType == SelfReference { return matchingNodes, nil } else if pathNode.PathElement.PathElementType == PathKey || pathNode.PathElement.PathElementType == ArrayIndex { return d.traverse(matchingNodes, pathNode.PathElement) } else { handler := d.operatorHandlers[pathNode.PathElement.OperationType] if handler != nil { return handler(d, matchingNodes, pathNode) } return nil, fmt.Errorf("Unknown operator %v", pathNode.PathElement.OperationType) } }