Generic ast (#1829)

Remove dependency on yaml.Node for internal AST representation. Yaml decoder is now just another decoder.

pkg/yqlib/decoder_yaml.go

@@ -20,8 +20,9 @@ type yamlDecoder struct {
 	leadingContent string
 	bufferRead     bytes.Buffer
 
-	readAnything bool
-	firstFile    bool
+	readAnything  bool
+	firstFile     bool
+	documentIndex uint
 }
 
 func NewYamlDecoder(prefs YamlPreferences) Decoder {
@@ -93,12 +94,14 @@ func (dec *yamlDecoder) Init(reader io.Reader) error {
 	dec.readAnything = false
 	dec.decoder = *yaml.NewDecoder(readerToUse)
 	dec.firstFile = false
+	dec.documentIndex = 0
 	return nil
 }
 
 func (dec *yamlDecoder) Decode() (*CandidateNode, error) {
-	var dataBucket yaml.Node
-	err := dec.decoder.Decode(&dataBucket)
+	var yamlNode yaml.Node
+	err := dec.decoder.Decode(&yamlNode)
+
 	if errors.Is(err, io.EOF) && dec.leadingContent != "" && !dec.readAnything {
 		// force returning an empty node with a comment.
 		dec.readAnything = true
@@ -116,28 +119,27 @@ func (dec *yamlDecoder) Decode() (*CandidateNode, error) {
 		return nil, err
 	}
 
-	candidateNode := &CandidateNode{
-		Node: &dataBucket,
+	candidateNode := CandidateNode{document: dec.documentIndex}
+	// don't bother with the DocumentNode
+	err = candidateNode.UnmarshalYAML(yamlNode.Content[0], make(map[string]*CandidateNode))
+	if err != nil {
+		return nil, err
 	}
 
+	candidateNode.HeadComment = yamlNode.HeadComment + candidateNode.HeadComment
+	candidateNode.FootComment = yamlNode.FootComment + candidateNode.FootComment
+
 	if dec.leadingContent != "" {
 		candidateNode.LeadingContent = dec.leadingContent
 		dec.leadingContent = ""
 	}
 	dec.readAnything = true
-	// move document comments into candidate node
-	// otherwise unwrap drops them.
-	candidateNode.TrailingContent = dataBucket.FootComment
-	dataBucket.FootComment = ""
-	return candidateNode, nil
+	dec.documentIndex++
+	return &candidateNode, nil
 }
 
 func (dec *yamlDecoder) blankNodeWithComment() *CandidateNode {
-	return &CandidateNode{
-		Document:       0,
-		Filename:       "",
-		Node:           &yaml.Node{Kind: yaml.DocumentNode, Content: []*yaml.Node{{Tag: "!!null", Kind: yaml.ScalarNode}}},
-		FileIndex:      0,
-		LeadingContent: dec.leadingContent,
-	}
+	node := createScalarNode(nil, "")
+	node.LeadingContent = dec.leadingContent
+	return node
 }