Added "debug-node-info" flag for inspecting yq AST

pkg/yqlib/printer_node_info.go

@@ -0,0 +1,76 @@
+package yqlib
+
+import (
+	"bufio"
+	"container/list"
+	"io"
+
+	"go.yaml.in/yaml/v3"
+)
+
+type nodeInfoPrinter struct {
+	printerWriter  PrinterWriter
+	appendixReader io.Reader
+	printedMatches bool
+}
+
+func NewNodeInfoPrinter(printerWriter PrinterWriter) Printer {
+	return &nodeInfoPrinter{
+		printerWriter: printerWriter,
+	}
+}
+
+func (p *nodeInfoPrinter) SetNulSepOutput(_ bool) {
+}
+
+func (p *nodeInfoPrinter) SetAppendix(reader io.Reader) {
+	p.appendixReader = reader
+}
+
+func (p *nodeInfoPrinter) PrintedAnything() bool {
+	return p.printedMatches
+}
+
+func (p *nodeInfoPrinter) PrintResults(matchingNodes *list.List) error {
+
+	for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		mappedDoc := el.Value.(*CandidateNode)
+		writer, errorWriting := p.printerWriter.GetWriter(mappedDoc)
+		if errorWriting != nil {
+			return errorWriting
+		}
+		bytes, err := yaml.Marshal(mappedDoc.ConvertToNodeInfo())
+		if err != nil {
+			return err
+		}
+		if _, err := writer.Write(bytes); err != nil {
+			return err
+		}
+		if _, err := writer.Write([]byte("\n")); err != nil {
+			return err
+		}
+		p.printedMatches = true
+		if err := writer.Flush(); err != nil {
+			return err
+		}
+	}
+
+	if p.appendixReader != nil {
+		writer, err := p.printerWriter.GetWriter(nil)
+		if err != nil {
+			return err
+		}
+
+		log.Debug("Piping appendix reader...")
+		betterReader := bufio.NewReader(p.appendixReader)
+		_, err = io.Copy(writer, betterReader)
+		if err != nil {
+			return err
+		}
+		if err := writer.Flush(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}