module main struct JsonParser { mut: js string tokens []string pos int tok_next int tok_super ?int } fn new_parser(qty int) JsonParser { return JsonParser{ tokens: []string{cap: qty} } } fn (mut p JsonParser) parse() int { j := p.tok_super or { 999 } return j } fn test_main() { mut x := new_parser(100) i := x.parse() assert i == 999 }