Hadrian Data Format

PFA by itself does not define a data representation, only a type system (Avro's type system). Hadrian, as a software library rather than an application, does not require data to be serialized in a particular format. Three input formats are defined so far (Avro, JSON, and CSV), but applications using the library are encouraged to use their own input formats: anything that is appropriate for the workflow that Hadrian is to be embedded in.

However, data has to be represented in some form for processing by PFA functions. This is the data format used internally by Hadrian.

Avro type	Hadrian's internal format
null	null Java Object
boolean	java.lang.Boolean
int	java.lang.Integer
long	java.lang.Long
float	java.lang.Float
double	java.lang.Double
string	Java String
bytes	Java array of bytes
array	com.opendatagroup.hadrian.data.PFAArray
map	com.opendatagroup.hadrian.data.PFAMap
record	com.opendatagroup.hadrian.data.PFARecord
fixed	com.opendatagroup.hadrian.data.PFAFixed
enum	com.opendatagroup.hadrian.data.PFAEnumSymbols
union	Java Object