[refactoring] update ast structure of "Return" node

pkg/ast/node.go

@@ -618,7 +618,9 @@ func (n *StmtPropertyList) Accept(v NodeVisitor) {
 // StmtReturn node
 type StmtReturn struct {
 	Node
-	Expr Vertex
+	ReturnTkn    *token.Token
+	Expr         Vertex
+	SemiColonTkn *token.Token
 }
 
 func (n *StmtReturn) Accept(v NodeVisitor) {

pkg/ast/visitor/filter_tokens.go

@@ -173,3 +173,8 @@ func (v *FilterTokens) StmtContinue(n *ast.StmtContinue) {
 	n.ContinueTkn = nil
 	n.SemiColonTkn = nil
 }
+
+func (v *FilterTokens) StmtReturn(n *ast.StmtReturn) {
+	n.ReturnTkn = nil
+	n.SemiColonTkn = nil
+}

pkg/printer/printer.go

@@ -2690,21 +2690,15 @@ func (p *Printer) printStmtProperty(n ast.Vertex) {
 	p.printFreeFloating(nn, token.End)
 }
 
-func (p *Printer) printStmtReturn(n ast.Vertex) {
-	nn := n.(*ast.StmtReturn)
-	p.printFreeFloating(nn, token.Start)
+func (p *Printer) printStmtReturn(n *ast.StmtReturn) {
+	p.printToken(n.ReturnTkn, "return")
 
-	io.WriteString(p.w, "return")
-	p.bufStart = " "
-	p.Print(nn.Expr)
-	p.printFreeFloating(nn, token.Expr)
-
-	p.printFreeFloating(nn, token.SemiColon)
-	if n.GetNode().Tokens.IsEmpty() {
-		io.WriteString(p.w, ";")
+	if n.Expr != nil {
+		p.bufStart = " "
 	}
+	p.Print(n.Expr)
 
-	p.printFreeFloating(nn, token.End)
+	p.printToken(n.SemiColonTkn, ";")
 }
 
 func (p *Printer) printStmtStaticVar(n ast.Vertex) {