[rust][8.0] Pattern match over a window instead
diff --git a/rust/src/day_08.rs b/rust/src/day_08.rs
index 252c64e..741d026 100644
--- a/rust/src/day_08.rs
+++ b/rust/src/day_08.rs
@@ -27,26 +27,25 @@ pub fn solve(input: &str) -> usize {
fn decode(string: &str) -> String {
let mut out = "".to_owned();
- let mut it = string[1..string.len()-1].chars();
+
+ let mut chars = string.chars().map(|c| Some(c)).collect::<Vec<_>>();
+ chars.append(&mut vec![None, None, None]);
+ let mut it = chars.windows(4);
loop {
- let c = match it.next() {
- Some('\\') => {
- match it.next() {
- Some('\\') => '\\',
- Some('"') => '"',
- Some('x') => {
- let mut b = it.next().and_then(|c| c.to_digit(16)).unwrap() << 4;
- b += it.next().and_then(|c| c.to_digit(16)).unwrap();
- b as u8 as char
- },
- Some(c) => panic!("Unexpected escaped char: {}", c),
- None => panic!("Unexpected end of string"),
- }
- }
- Some(c) => c,
- None => break,
+ match it.next() {
+ Some([Some('"'), None, None, None]) => break,
+ Some([Some('"'), _, _, _]) => {},
+ Some([Some('\\'), Some('\\'), _, _]) => { it.next(); out.push('\\'); },
+ Some([Some('\\'), Some('"'), _, _]) => { it.next(); out.push('"'); },
+ Some([Some('\\'), Some('x'), Some(a), Some(b)]) => {
+ it.next(); it.next(); it.next();
+ let c = (a.to_digit(16).unwrap_or(0) << 4) + (b.to_digit(16).unwrap_or(0));
+ out.push(c as u8 as char);
+ },
+ Some([Some(c), _, _, _]) => { out.push(c); },
+ Some(x) => panic!("{:?}", x),
+ None => panic!(""),
};
- out.push(c);
}
out
}