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pub struct Stack {
pub mem: [u8; 256],
pub sp: u8,
}
impl Stack {
pub fn new() -> Self {
Self {
mem: [0; 256],
sp: 0,
}
}
pub fn push_u8(&mut self, val: u8) {
self.mem[self.sp as usize] = val;
self.sp = self.sp.wrapping_add(1);
}
pub fn pop_u8(&mut self) -> u8 {
self.sp = self.sp.wrapping_sub(1);
self.mem[self.sp as usize]
}
pub fn push_u16(&mut self, val: u16) {
let [byte_high, byte_low] = u16::to_be_bytes(val);
self.push_u8(byte_high);
self.push_u8(byte_low);
}
pub fn pop_u16(&mut self) -> u16 {
self.sp = self.sp.wrapping_sub(1);
let byte_low = self.mem[self.sp as usize];
self.sp = self.sp.wrapping_sub(1);
let byte_high = self.mem[self.sp as usize];
u16::from_be_bytes([byte_high, byte_low])
}
pub fn get_u8(&mut self) -> u8 {
self.mem[self.sp.wrapping_sub(1) as usize]
}
pub fn get_u16(&mut self) -> u16 {
let byte_low = self.mem[self.sp.wrapping_sub(1) as usize];
let byte_high = self.mem[self.sp.wrapping_sub(2) as usize];
u16::from_be_bytes([byte_high, byte_low])
}
pub fn reset(&mut self) {
self.mem.fill(0);
self.sp = 0;
}
}
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