update README.md

visitor/dumper.go

@@ -0,0 +1,67 @@
+package visitor
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/z7zmey/php-parser/node"
+	"github.com/z7zmey/php-parser/position"
+
+	"github.com/z7zmey/php-parser/comment"
+	"github.com/z7zmey/php-parser/walker"
+)
+
+func isWalkerImplementsNodeInterface(w walker.Walker) bool {
+	switch w.(type) {
+	case node.Node:
+		return true
+	default:
+		return false
+	}
+}
+
+// Dumper prints ast hierarchy to stdout
+// Also prints comments and positions attached to nodes
+type Dumper struct {
+	Indent    string
+	Comments  comment.Comments
+	Positions position.Positions
+}
+
+// EnterNode is invoked at every node in heirerchy
+func (d Dumper) EnterNode(w walker.Walker) bool {
+	if !isWalkerImplementsNodeInterface(w) {
+		return false
+	}
+
+	n := w.(node.Node)
+
+	fmt.Printf("%v%v", d.Indent, reflect.TypeOf(n))
+	if p := d.Positions[n]; p != nil {
+		fmt.Printf(" %v", *p)
+	}
+	if a := n.Attributes(); len(a) > 0 {
+		fmt.Printf(" %v", a)
+	}
+	fmt.Println()
+
+	if c := d.Comments[n]; len(c) > 0 {
+		fmt.Printf("%vComments:\n", d.Indent+"  ")
+		for _, cc := range c {
+			fmt.Printf("%v%q\n", d.Indent+"    ", cc)
+		}
+	}
+
+	return true
+}
+
+// GetChildrenVisitor is invoked at every node parameter that contains children nodes
+func (d Dumper) GetChildrenVisitor(key string) walker.Visitor {
+	fmt.Printf("%v%q:\n", d.Indent+"  ", key)
+	return Dumper{d.Indent + "    ", d.Comments, d.Positions}
+}
+
+// LeaveNode is invoked after node process
+func (d Dumper) LeaveNode(n walker.Walker) {
+	// do nothing
+}