92 lines
2.5 KiB
Rust
92 lines
2.5 KiB
Rust
pub fn filter_substring<'a>(needle: &str, haystack: &Vec<&'a str>) -> Vec<&'a str> {
|
|
return haystack
|
|
.iter()
|
|
.filter(|s| s.contains(needle))
|
|
.cloned()
|
|
.collect();
|
|
}
|
|
|
|
pub fn filter_subsequence<'a>(needle: &str, haystack: &Vec<&'a str>) -> Vec<&'a str> {
|
|
return haystack
|
|
.iter()
|
|
.filter(|s| is_subsequence(needle, s))
|
|
.cloned()
|
|
.collect();
|
|
}
|
|
|
|
fn is_subsequence(needle: &str, string: &str) -> bool {
|
|
// we need to explicitly convert here to iterate over chars
|
|
// (UTF-8, so possibly multiple bytes long)
|
|
let mut chars = string.chars();
|
|
let needle_chars = needle.chars();
|
|
for nc in needle_chars {
|
|
loop {
|
|
match chars.next() {
|
|
Some(current) => {
|
|
// if the character matches, break and continue with the next nc
|
|
if current == nc {
|
|
break;
|
|
}
|
|
}
|
|
_ => return false
|
|
}
|
|
}
|
|
}
|
|
true
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use crate::{
|
|
filter_substring,
|
|
filter_subsequence
|
|
};
|
|
|
|
#[test]
|
|
fn test_filter_substring_single() {
|
|
let needle = "sdf";
|
|
let hay = vec!["asdf", "qwer"];
|
|
let expected = vec!["asdf"];
|
|
assert_eq!(filter_substring(&needle, &hay), expected);
|
|
}
|
|
|
|
#[test]
|
|
fn test_filter_substring_none() {
|
|
let needle = "sdf";
|
|
let hay = vec!["qwertz"];
|
|
let expected: Vec<&str> = Vec::new();
|
|
assert_eq!(filter_substring(&needle, &hay), expected);
|
|
}
|
|
|
|
#[test]
|
|
fn test_filter_substring_multiple() {
|
|
let needle = "sdf";
|
|
let hay = vec!["asdf", "asd", "sdfg", "dfgh"];
|
|
let expected = vec!["asdf", "sdfg"];
|
|
assert_eq!(filter_substring(&needle, &hay), expected);
|
|
}
|
|
|
|
#[test]
|
|
fn test_filter_subsequence_single() {
|
|
let needle = "asa";
|
|
let hay = vec!["aaass", "aasda"];
|
|
let expected = vec!["aasda"];
|
|
assert_eq!(filter_subsequence(&needle, &hay), expected);
|
|
}
|
|
|
|
#[test]
|
|
fn test_filter_subsequence_none() {
|
|
let needle = "asa";
|
|
let hay = vec!["aas"];
|
|
let expected: Vec<&str> = Vec::new();
|
|
assert_eq!(filter_subsequence(&needle, &hay), expected);
|
|
}
|
|
|
|
#[test]
|
|
fn test_filter_subsequence_multiple() {
|
|
let needle = "asa";
|
|
let hay = vec!["asa", "assa", "qwerafwfsferfssaas"];
|
|
assert_eq!(filter_subsequence(&needle, &hay), hay);
|
|
}
|
|
}
|