mirror of https://github.com/rust-lang/rust.git
71 lines
1.7 KiB
Rust
71 lines
1.7 KiB
Rust
//@ known-bug: #102310
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//@ compile-flags: -Copt-level=0
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//@ edition:2021
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// ignore-tidy-linelength
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use std::vec::Vec;
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use std::iter::Peekable;
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pub fn main() {
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let packet = decode(vec![1,0,1,0]);
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}
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pub fn decode(bitstream: Vec<u64>) -> Packet {
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let mut bitstream_itr = bitstream.into_iter().peekable();
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return match decode_packet(&mut bitstream_itr) {
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Some(p) => p,
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None => panic!("expected outer packet"),
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}
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}
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pub fn decode_packets<I: Iterator<Item = u64>>(itr: &mut Peekable<I>) -> Vec<Packet> {
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let mut res = Vec::new();
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loop {
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match decode_packet(itr) {
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Some(p) => { res.push(p); },
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None => break
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}
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}
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return res;
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}
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pub fn decode_packet<I: Iterator<Item = u64>>(itr: &mut Peekable<I>) -> Option<Packet> {
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// get version digits
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let version = extend_number(0, itr, 3)?;
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let type_id = extend_number(0, itr, 3)?;
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return operator_packet(version, type_id, itr);
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}
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pub fn operator_packet<I: Iterator<Item = u64>>(version: u64, type_id: u64, itr: &mut Peekable<I>) -> Option<Packet> {
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let p = OperatorPacket {
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version: version,
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type_id: type_id,
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packets: decode_packets(&mut itr.take(0).peekable()),
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};
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return Some(Packet::Operator(p));
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}
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pub fn extend_number<I: Iterator<Item = u64>>(num: u64, itr: &mut Peekable<I>, take: u64) -> Option<u64> {
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let mut value = num;
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for _ in 0..take {
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value *= 2;
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value += itr.next()?;
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}
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return Some(value);
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}
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#[derive(Debug)]
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pub enum Packet {
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Operator(OperatorPacket),
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}
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#[derive(Debug)]
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pub struct OperatorPacket {
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version: u64,
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type_id: u64,
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packets: Vec<Packet>
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}
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