Added #[generate(Debug)] feature

[diondokter]

Closes #8

You can now do this:

implement_registers!(
    MyDevice.registers<u8> = {
        // (comments must go first)
        #[generate(Debug)]              // <- new!
        id(RO, 0, 3) = MSB {
            manufacturer: u16:LE as Manufacturer = RW 0..16,
            version: u8:NE = RO 16..20,
            edition: u8:BE = RO 20..24,
        },
    }
);

Then we can:

let id = device.registers().id().read()?;
println!("{:?}", id);

id::R { raw: 0x010065, manufacturer: Ok(CarmineCrystal), version: 6, edition: 5 }

The generate attribute is optional. If you don't add it to the register, the output is now better too:

id::R { raw: 0x010065 }

When opting in, all field types must impl Debug.

This attribute syntax can be used later for other things as well.

[diondokter]

I'm now just noticing it... The field values that are just a number are in decimal. All other numbers are Hex. Will this be a problem?
It's only the raw bit values that are hex and they're all prepended with 0x, so I think that's fine.
In the end you're supposed to leave numbers as numbers. Anywhere where the bits are important (so you'd want to see the hex fmt) should be encoded in enums anyways.

[korken89]

These need to be changed so paths are internal to the macro

[diondokter]

Good you spotted that!

[korken89]

Now it works when I test it!