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macro_rules! then_inc {
($v:expr) => {{
$v = $v.wrapping_add(1);
$v as usize
}};
}
pub struct ScratchDevice {
memory: Vec<u8>,
pub max_capacity: u32,
pub pointer_1: u32,
pub pointer_2: u32,
}
impl ScratchDevice {
pub fn new() -> Self {
Self {
memory: Vec::new(),
max_capacity: 16 * 65536,
pointer_1: 0,
pointer_2: 0,
}
}
pub fn read_head_1(&mut self) -> u8 {
let i = then_inc!(self.pointer_1);
self.read_byte(i)
}
pub fn read_head_2(&mut self) -> u8 {
let i = then_inc!(self.pointer_2);
self.read_byte(i)
}
pub fn write_head_1(&mut self, value: u8) {
let i = then_inc!(self.pointer_1);
self.write_byte(i, value);
}
pub fn write_head_2(&mut self, value: u8) {
let i = then_inc!(self.pointer_2);
self.write_byte(i, value);
}
fn read_byte(&self, pointer: usize) -> u8 {
match self.memory.get(pointer as usize) {
Some(value) => *value,
None => 0,
}
}
fn write_byte(&mut self, pointer: usize, value: u8) {
if pointer < self.max_capacity as usize {
if pointer >= self.memory.len() {
self.memory.resize(pointer + 1, 0);
}
self.memory[pointer] = value;
}
}
}
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