FutureSDR Macros

Procedural macros for FutureSDR applications and custom blocks.

connect!

connect! adds blocks to a flowgraph if needed and wires stream, local-stream, message, and circuit connections.

connect!(fg,
    src > head > snk;
    msg_source | msg_sink;
);

Default stream ports are output and input. Default message ports are out and in. Named ports can be written on either side of a connection:

connect!(fg,
    src.samples > input.filter.output > snk;
    control.out | command.radio;
);

Connection operators:

• >: send-capable stream connection.
• ~>: local-domain-only stream connection for non-Send buffers.
• |: message connection.
• <: close an in-place circuit return path after the forward stream path has already been connected.

Blocks without connections can be listed on their own line:

connect!(fg, monitor);

#[derive(Block)]

Derive the runtime interface for a block kernel. Annotated fields become stream ports, and struct-level attributes declare message ports:

#[derive(Block)]
#[message_inputs(set_gain)]
#[message_outputs(done)]
struct Scale {
    #[input]
    input: DefaultCpuReader<f32>,
    #[output]
    output: DefaultCpuWriter<f32>,
    gain: f32,
}

The struct implements Kernel; the derive macro supplies the generated port metadata, stream initialization and validation, dynamic stream lookup, and message-handler dispatch.

Supported attributes:

• #[input] and #[output] on fields.
• #[message_inputs(handler)].
• #[message_inputs(handler = "port-name")].
• #[message_outputs(out)].
• #[blocking].
• #[type_name(Name)].
• #[null_kernel].