Wire format

Packed and canonical

Packed is byte-identical to Cap’n C++ PackedOutputStream / capnp convert binary:packed (AddressBook golden), including the C++ 0xFF extra-word heuristic.

Canonical form (capnp_canonicalize) is byte-identical to capnp convert binary:canonical on AddressBook.

Empty struct writes B=-1 (0xFFFFFFFC), same as c-capnproto and capnp-fortran.

Schema-order encode

test/test_addressbook.c sets fields in schema order and memcmp=s =addressbook_alice_bob.bin from official capnp encode.

List evolution

Same cases as Cap’n C++ and capnp-fortran:

Writer encoded	Reader asks for	API
List(UInt8/16/32/64)	List(Struct) with scalar @0	capnp_list_get_struct then capnp_get_u*
List(pointer) e.g. List(Text)	List(Struct) with pointer @0	capnp_list_get_struct then capnp_get_text / capnp_getp
List(Struct) with data word 0	List(UInt*) field @0	capnp_list_get_u8 / u16 / u32 / u64 / f64
List(Struct) with pointer 0	List(Text) / pointer list	capnp_list_get_text

List(Bool) and List(Void) do not upgrade to struct views. Tests: test/test_list_evolution.c.

Samples

Suite	Schema	What
addressbook	schema/addressbook.capnp	Alice/Bob, phones, employment union
calculator	schema/calculator.capnp	Expression trees (serialization only)
wire / list_text	demo shapes	core reader/builder

Calculator RPC (interfaces, pipelining) is out of scope.