baryuxn 0.3.0

An implementation of the Uxn stack machine as a no_std library.
Documentation 
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use crate::machine::UxnMachineState;

/// Uxn interacts with the outside world using devices.
///
/// These are implementation defined in the form of a trait that satisfies:
/// - reading bytes from addresses 0 to 255
/// - writing bytes from addresses 0 to 255
///
/// The trait automatically provides methods for writing and reading shorts, but these
/// can be overriden if necessary.
pub trait UxnDeviceBus {
    /// Reads a single byte from the device bus.
    fn read(&mut self, machine: &mut UxnMachineState, address: u8) -> u8;
    /// Writes a single byte to the device bus.
    fn write(&mut self, machine: &mut UxnMachineState, address: u8, byte: u8);

    /// Reads a short from the device bus
    fn read_short(&mut self, machine: &mut UxnMachineState, address: u8) -> u16 {
        u16::from_be_bytes([
            self.read(machine, address),
            self.read(machine, address.wrapping_add(1)),
        ])
    }

    /// Writes a short to the device bus.
    fn write_short(&mut self, machine: &mut UxnMachineState, address: u8, short: u16) {
        let [msb, lsb] = short.to_be_bytes();
        self.write(machine, address, msb);
        self.write(machine, address.wrapping_add(1), lsb);
    }
}