refactoring: update ast structure of "ArrayItem" node

pkg/ast/node.go

@@ -1177,6 +1177,7 @@ type ExprArrayItem struct {
 	EllipsisTkn    *token.Token
 	Key            Vertex
 	DoubleArrowTkn *token.Token
+	AmpersandTkn   *token.Token
 	Val            Vertex
 }
 

pkg/ast/visitor/dumper.go

@@ -1056,6 +1056,7 @@ func (v *Dumper) ExprArrayItem(n *ast.ExprArrayItem) {
 	v.dumpToken("EllipsisTkn", n.EllipsisTkn)
 	v.dumpVertex("Key", n.Key)
 	v.dumpToken("DoubleArrowTkn", n.DoubleArrowTkn)
+	v.dumpToken("AmpersandTkn", n.AmpersandTkn)
 	v.dumpVertex("Val", n.Val)
 
 	v.indent--

pkg/ast/visitor/printer.go

@@ -641,6 +641,7 @@ func (p *printer) ExprArrayItem(n *ast.ExprArrayItem) {
 	p.printToken(n.EllipsisTkn, nil)
 	p.printNode(n.Key)
 	p.printToken(n.DoubleArrowTkn, p.ifNode(n.Key, []byte("=>")))
+	p.printToken(n.AmpersandTkn, nil)
 	p.printNode(n.Val)
 }
 

pkg/ast/visitor/printer_test.go

@@ -1559,9 +1559,31 @@ func TestPrinterPrintExprArrayItem(t *testing.T) {
 
 	p := visitor.NewPrinter(o).WithState(visitor.PrinterStatePHP)
 	n := &ast.ExprArrayItem{
-		Val: &ast.ExprReference{Var: &ast.ExprVariable{
+		Val: &ast.ExprVariable{
 			VarName: &ast.Identifier{Value: []byte("$world")},
-		}},
+		},
+	}
+	n.Accept(p)
+
+	expected := `$world`
+	actual := o.String()
+
+	if expected != actual {
+		t.Errorf("\nexpected: %s\ngot: %s\n", expected, actual)
+	}
+}
+
+func TestPrinterPrintExprArrayItem_Reference(t *testing.T) {
+	o := bytes.NewBufferString("")
+
+	p := visitor.NewPrinter(o).WithState(visitor.PrinterStatePHP)
+	n := &ast.ExprArrayItem{
+		AmpersandTkn: &token.Token{
+			Value: []byte("&"),
+		},
+		Val: &ast.ExprVariable{
+			VarName: &ast.Identifier{Value: []byte("$world")},
+		},
 	}
 	n.Accept(p)