The primary interface to encode data in Go is through the use of the generated Marshal function. This function has the same signature as that found in the Go encoding/asn1 package:

func Marshal(val interface{}) ([]byte, error)

The val argument holds a value of the type to be encoded. Note that the Marshal function only encodes types determined to be Protocol Data Unit (PDU) types. By default, a PDU type in a schema is a type not found to be referenced by any other type. This behavior can be overridden by using the -pdu command-line option to explicitly select types as PDU types.

The Marshal function returns the encoded message in memory as a byte slice. If any errors occur during encoding, the error result is returned in the error return value. The encoded value byte slice will be nil in this case.