Attribute Macro read

#[read]

Macro deriving a ReadState implementation for the destination state type, consuming a message of message_type and the current state, as indicated by the transition tuple.

Example:

#[hax_lib_protocol_macros::read(A1, A2, Message)]
fn read_pong(_state: A1, msg: Message) -> ::hax_lib_protocol::ProtocolResult<A2> {
    match msg {
        Message::Ping(_) => Err(::hax_lib_protocol::ProtocolError::InvalidMessage),
        Message::Pong(received) => Ok(A2 { received }),
    }
}
// The following is generated by the macro:
#[hax_lib::exclude]
impl TryFrom<(A1, Message)> for A2 {
    type Error = ::hax_lib_protocol::ProtocolError;
    fn try_from((state, msg): (A1, Message)) -> Result<Self, Self::Error> {
        read_pong(state, msg)
    }
}
#[hax_lib::exclude]
impl ReadState<A2> for A1 {
    type Message = Message;
    fn read(self, msg: Message) -> ::hax_lib_protocol::ProtocolResult<A2> {
        A2::try_from((self, msg))
    }
}