decode.go
func NewDecoder(p Parser) *Decoder {
	if p == nil {
		panic("objconv: the parser is nil")
	}
	return &Decoder{Parser: p}
}
func NewDecoder(p Parser) *Decoder {
	if p == nil {
		panic("objconv: the parser is nil")
	}
	return &Decoder{Parser: p}
}
// NewDecoder returns a decoder object that uses p, will panic if p is nil.