rust_assembler/str/
remove_matches.rs

1
2/// Replaces multiple `str` at once, avoiding intermediate allocations. It returns a new `String` containing the result. Values passed by value keep ownership.
3/// 
4/// # Examples
5/// 
6/// ```
7/// 
8/// let s = "Ciao bello";
9/// 
10/// let s_removed = remove_matches!( s; "ia", "b" );
11/// 
12/// assert_eq!(s_removed, "Co ello");
13#[macro_export]
14macro_rules! remove_matches {
15    ( $string:expr; $( $pat:expr ),* ) => ({
16        let mut new_string: String = String::new();
17
18        let mut to_skip = 0;
19        let mut next_start = 0;
20        
21        'outer: for i in 0..$string.len() {
22            if to_skip > 0 {
23                to_skip -= 1;
24                continue 'outer
25            }
26
27            $(
28                unsafe {
29                    // It's the element that must be replaced.
30                    
31                    let pat_len = $pat.len();
32                    // Avoids out of bounds bugs.
33                    if i + pat_len > $string.len() { break 'outer }
34
35                    // This is safe thanks to the check above.
36                    if *$pat == *$string.get_unchecked(i..i + pat_len) {
37                        new_string.push_str( $string.get_unchecked(next_start..i));
38                        next_start = i + pat_len;
39                        to_skip += pat_len - 1;
40                    }
41                }
42            )*
43            
44        }
45        
46        unsafe {
47            new_string.push_str($string.get_unchecked(next_start..));
48        }
49
50        new_string
51    });
52}
rust_assembler/str/remove_matches.rs

rust_assembler/str/
remove_matches.rs
