Macro to generate record and matching @type

Questions / Help
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1

I’m looking for some pointers on how to inject a fully customized @type and defrecord definitions from macro.

I’m creating a <<binary>> <-> record() serializer/deserializer generating code based on a textual description of data structure, not far from the idea of ProtoBuf (but with a much simpler binary representation). For each form I’d like to generate a record, a matching typedef and serialize(record) / deserialize(binary) functions.

Function generation part I have mostly sorted out, just type/record generation is missing. I figured out how to manually write the necessary AST, I just want to know if there’s some quote/unquote magic to make that the elegant way, as is suitable for the elegant language Elixir is.

My plan is to transform this:

protocol = [
sata_id_rep: [
      cmd: @cmd_sata_id,
      fields: [
        {:channel, :int, 8, port()},
        {:data, :bin, 512, sector()},
        {:ata_status, :bin, 32, ata_status()}
      ]
    ]
 ]

into this:

Record.defrecord(:sata_id_rep, channel: nil, data: nil, ata_status: nil)

@type sata_id_rep :: record(:sata_id_rep, channel: port(), data: sector(), ata_status: ata_status())

def serialize(sata_id_rep(channel: channel, data: data, ata_status: ata_status)) do
    <<@sata_id_rep,channel::8,data::binary-size(512),ata_status::binary-size(32)>>
end

def deserialize(<<@sata_id_rep,channel::8,data::binary-size(512),ata_status::binary-size(32)>>) do
    sata_id_rep(channel: channel, data: data, ata_status: ata_status)
end

For example: how to express inquote that in @type the first occurrence of sata_id_rep is without colon and the second one with one.

P.S. Of course I did read Metaprogramming Elixir. Didn’t help in my case. I’ve also inspected the source code of typed-struct which didn’t help either (they work with Structs and @type has a fixed name t).

Thanks in advance,

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