FutureSDR Macros
================
Macros to make working with FutureSDR a bit nicer.
## Connect Macro
Avoid boilerplate when setting up the flowgraph. This macro simplifies adding
blocks to the flowgraph and connecting them.
Assume you have created a flowgraph `fg` and several blocks (`src`, `shift`, ...) and need to add the block to the flowgraph and connect them. Using the `connect!` macro, this can be done with:
```rust
connect!(fg,
src.out > shift.in;
shift > resamp1 > demod;
demod > resamp2 > snk;
);
```
It generates the following code:
```rust
// Add all the blocks to the `Flowgraph`...
let src = fg.add_block(src);
let shift = fg.add_block(shift);
let resamp1 = fg.add_block(resamp1);
let demod = fg.add_block(demod);
let resamp2 = fg.add_block(resamp2);
let snk = fg.add_block(snk);
// ... and connect the ports appropriately
fg.connect_stream(src, "out", shift, "in")?;
fg.connect_stream(shift, "out", resamp1, "in")?;
fg.connect_stream(resamp1, "out", demod, "in")?;
fg.connect_stream(demod, "out", resamp2, "in")?;
fg.connect_stream(resamp2, "out", snk, "in")?;
```
Connections endpoints are defined by `block.port_name`. Standard names (i.e.,
`out`/`in`) can be omitted. When ports have different name than standard `in`
and `out`, one can use following notation.
Stream connections are indicated as `>`, while message connections are indicated as `|`.
It is possible to add blocks that have no connections by just putting them on a line separately.
``` rust
connect!(fg, dummy);
```
Port names with spaces have to be quoted.
```ignore
connect!(fg,
src."out port" > snk
);
```
## Message Handler Macro
Avoid boilerplate when creating message handlers.
Assume a block with a message handler that refers to a block function
`Self::my_handler`.
```ignore
pub fn new() -> Block {
Block::new(
BlockMetaBuilder::new("MyBlock").build(),
StreamIoBuilder::new().build(),
MessageIoBuilder::new()
.add_input("handler", Self::my_handler)
.build(),
Self,
)
}
```
The underlying machinery of the handler implementation is rather involved.
With the `message_handler` macro, it can be simplified to:
```ignore
#[message_handler]
async fn my_handler(
&mut self,
_io: &mut WorkIo,
_mio: &mut MessageIo<Self>,
_meta: &mut BlockMeta,
_p: Pmt,
) -> Result<Pmt> {
Ok(Pmt::Null)
}
```