Expressions

Any expression is either a variable reference, an application or a special form:

zodiac:varref : parsed (var)

zodiac:app : parsed (fun args)

zodiac:form : parsed ()

The var field of a varref is a Scheme symbol. The fun field of app is of type parsed, while args contains a list of parsed. All the special forms -- which are defined in other documents -- are sub-types of form.