Rust macro generated module

eight_segment.rs

#![macro_escape]

use safe_component::port::Port;

pub trait EightSegment {
    unsafe fn new() -> Self;
    fn display(&mut self, count: u32);
}

macro_rules! create_eight_segment (
    ($struct_name: ident,
    $seg_a: ident,
    $seg_b: ident,
    $seg_c: ident,
    $seg_d: ident,
    $seg_e: ident,
    $seg_f: ident,
    $seg_g: ident,
    $seg_dp: ident) => {{
        pub struct $struct_name;
        impl EightSegment for $struct_name {
            unsafe fn new() -> Self {
                $seg_a.set_pin_dir(true);
                $seg_b.set_pin_dir(true);
                $seg_c.set_pin_dir(true);
                $seg_d.set_pin_dir(true);
                $seg_e.set_pin_dir(true);
                $seg_f.set_pin_dir(true);
                $seg_g.set_pin_dir(true);
                $seg_dp.set_pin_dir(true);
                let mut eight_segment = $struct_name;
                eight_segment.display(0);
                eight_segment
            }

            fn display(&mut self, count: u32) {
                let (seg_e_on, seg_d_on, seg_c_on, seg_dp_on, seg_b_on, seg_a_on, seg_f_on, seg_g_on) = match count {
                    0 => (true, true, true, false, true, true, true, false),
                    1 => (false, false, true, false, true, false, false, false),
                    2 => (true, true, false, false, true, true, false, true),
                    3 => (false, true, true, false, true, true, false, true),
                    4 => (false, false, true, false, true, false, true, true),
                    5 => (false, true, true, false, false, true, true, true),
                    6 => (true, true, true, false, false, true, true, true),
                    7 => (false, false, true, false, true, true, false, false),
                    8 => (true, true, true, false, true, true, true, true),
                    9 => (false, false, true, false, true, true, true, true),
                    _ => (true, true, true, true, true, true, true, true),
                };

                unsafe {
                    $seg_a.set_pin_out(!seg_a_on);
                    $seg_b.set_pin_out(!seg_b_on);
                    $seg_c.set_pin_out(!seg_c_on);
                    $seg_d.set_pin_out(!seg_d_on);
                    $seg_e.set_pin_out(!seg_e_on);
                    $seg_f.set_pin_out(!seg_f_on);
                    $seg_g.set_pin_out(!seg_g_on);
                    $seg_dp.set_pin_out(!seg_dp_on);
                }
            }
        }
        $struct_name::new()
    }}
);

EightSegmentGenerated.rs

// note: the pins are defined as `const` here but in the macro expansion are inlined
const SEG_A: Port = D7;
const SEG_B: Port = D6;
const SEG_C: Port = D3;
const SEG_D: Port = D4;
const SEG_E: Port = D5;
const SEG_F: Port = D8;
const SEG_G: Port = D9;
const SEG_DP: Port = D2;

pub struct EightSegment1;

impl EightSegment for EightSegment1 {
    unsafe fn new() -> Self {
        unsafe {
            SEG_A.set_pin_dir(true);
            SEG_B.set_pin_dir(true);
            SEG_C.set_pin_dir(true);
            SEG_D.set_pin_dir(true);
            SEG_E.set_pin_dir(true);
            SEG_F.set_pin_dir(true);
            SEG_G.set_pin_dir(true);
            SEG_DP.set_pin_dir(true);
            seg_num(0);        
        }
        let eight_segment = EightSegment1;
        eight_segment.display(0);
        eight_segment

    }

    fn display(&mut self, count: u32) {
        unsafe {
            let (SEG_E_on, SEG_D_on, SEG_C_on, SEG_DP_on, SEG_B_on, SEG_A_on, SEG_F_on, SEG_G_on) = match count {
            0 => (true, true, true, false, true, true, true, false),
            1 => (false, false, true, false, true, false, false, false),
            2 => (true, true, false, false, true, true, false, true),
            3 => (false, true, true, false, true, true, false, true),
            4 => (false, false, true, false, true, false, true, true),
            5 => (false, true, true, false, false, true, true, true),
            6 => (true, true, true, false, false, true, true, true),
            7 => (false, false, true, false, true, true, false, false),
            8 => (true, true, true, false, true, true, true, true),
            9 => (false, false, true, false, true, true, true, true),
            _ => (true, true, true, true, true, true, true, true),
        };

        SEG_A.set_pin_out(!SEG_A_on);
        SEG_B.set_pin_out(!SEG_B_on);
        SEG_C.set_pin_out(!SEG_C_on);
        SEG_D.set_pin_out(!SEG_D_on);
        SEG_E.set_pin_out(!SEG_E_on);
        SEG_F.set_pin_out(!SEG_F_on);
        SEG_G.set_pin_out(!SEG_G_on);
        SEG_DP.set_pin_out(!SEG_DP_on);
        }
    }
}

main.rs

fn main() {
  let mut digit = unsafe {
    create_eight_segment!(EightSegment2, D7, D6, D3, D4, D5, D8, D9, D2)
  };
  loop {
    let s = ...
    digit.display(s);
  }
}