use std::ops::{Add, Sub};

pub trait Ram {
    fn as_ram_ptr<'a>(&'a self) -> RamPtr<'a>;
}

impl Ram for [u8; 65536] {
    fn as_ram_ptr<'a>(&'a self) -> RamPtr<'a> {
        RamPtr { ram: self, ptr: 0 }
    }
}

pub struct RamPtr<'a> {
    ram: &'a [u8; 65536],
    ptr: u16,
}

impl Add<usize> for RamPtr<'_> {
    type Output = Self;

    fn add(mut self, rhs: usize) -> Self::Output {
        self.ptr = self.ptr.wrapping_add(rhs as u16);
        self
    }
}

impl Sub<usize> for RamPtr<'_> {
    type Output = Self;

    fn sub(mut self, rhs: usize) -> Self::Output {
        self.ptr = self.ptr.wrapping_sub(rhs as u16);
        self
    }
}