Add operator!

pkg/yqlib/operator_add.go

@@ -0,0 +1,69 @@
+package yqlib
+
+import (
+	"fmt"
+
+	"container/list"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+func toNodes(candidates *list.List) []*yaml.Node {
+
+	if candidates.Len() == 0 {
+		return []*yaml.Node{}
+	}
+	candidate := candidates.Front().Value.(*CandidateNode)
+
+	if candidate.Node.Tag == "!!null" {
+		return []*yaml.Node{}
+	}
+
+	switch candidate.Node.Kind {
+	case yaml.SequenceNode:
+		return candidate.Node.Content
+	default:
+		return []*yaml.Node{candidate.Node}
+	}
+
+}
+
+func AddOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+	log.Debugf("Add operator")
+	var results = list.New()
+	lhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Lhs)
+	if err != nil {
+		return nil, err
+	}
+	rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
+
+	if err != nil {
+		return nil, err
+	}
+
+	for el := lhs.Front(); el != nil; el = el.Next() {
+		lhsCandidate := el.Value.(*CandidateNode)
+		lhsNode := UnwrapDoc(lhsCandidate.Node)
+
+		var newBlank = &CandidateNode{
+			Path:     lhsCandidate.Path,
+			Document: lhsCandidate.Document,
+			Filename: lhsCandidate.Filename,
+			Node:     &yaml.Node{},
+		}
+
+		switch lhsNode.Kind {
+		case yaml.MappingNode:
+			return nil, fmt.Errorf("Maps not yet supported for addition")
+		case yaml.SequenceNode:
+			newBlank.Node.Kind = yaml.SequenceNode
+			newBlank.Node.Style = lhsNode.Style
+			newBlank.Node.Tag = "!!seq"
+			newBlank.Node.Content = append(lhsNode.Content, toNodes(rhs)...)
+			results.PushBack(newBlank)
+		case yaml.ScalarNode:
+			return nil, fmt.Errorf("Scalars not yet supported for addition")
+		}
+	}
+	return results, nil
+}