driver.rs

use std::io::{Read, Write, Seek};

// Driver is the basis for reading and writing words
// for use in the filesystem.
trait Driver {
    fn erase_sector(&self, n: u32) -> Result<(), &'static str>;
    fn erase_all_sectors(&self) -> Result<(), &'static str>;
    fn read_word(&self, addr: u32) -> Result<u16, &'static str>;
    fn write_word(&self, addr: u32, val: u16) -> Result<(), &'static str>;
}

struct ReadWriteSeekDriver<A: Read + Write + Seek> {
    driver: A,
    num_sec: u32
}

impl<A> ReadWriteSeekDriver<A> 
    where A: Read + Write + Seek {
    fn new(num_sec: u32, driver: A) -> Self {
        ReadWriteSeekDriver {
            num_sec: num_sec,
            driver: driver
        }
    }
}

impl<A> Driver for ReadWriteSeekDriver<A> 
    where A: Read + Write + Seek {
    fn erase_sector(&self, n: u32) -> Result<(), &'static str> { unimplemented!() }
    fn erase_all_sectors(&self) -> Result<(), &'static str> { unimplemented!() }
    fn read_word(&self, addr: u32) -> Result<u16, &'static str> { unimplemented!() }
    fn write_word(&self, addr: u32, val: u16) -> Result<(), &'static str> { unimplemented!() }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::io::Cursor;
    #[test]
    fn test_read_write_seek_driver_new() {
        let a = ReadWriteSeekDriver::new(20, Cursor::new(vec![1,2,3]));
        a.erase_all_sectors();
    }
}