Terser queries on OBR fields

[ConnorBarnhill]

Hi,

First off, thanks for contributing this package. Super helpful.

While using the ParseQuery method, I found myself doing the following:

for i, _ := range m.Segments("OBR") {
    OBRElementQuery, _ := hl7.ParseQuery(fmt.Sprintf("OBR(%d)-3", i + 1))
    OBRElement := OBRElementQuery.GetString(m)
}

I define/parse all of my other queries independent of the message but because the number of OBR segements varies I have to parse the query for each OBR segment of each message. Is there a better way to do this?