find_last.rs

//! This method is like `find` except that it iterates over elements of
//! `collection` from right to left.
//!
//! Example
//! ```
//! use lodash_rust::find_last;
//!
//! let res = find_last::new([1, 2, 3, 4].to_vec(), &|x: i32| x % 2 == 1, 3);
//! println!("{res:?}") // Some(3)
//! ```

pub fn new<T: Copy>(array: Vec<T>, f: &dyn Fn(T) -> bool, from_index: usize) -> Option<T> {
    if from_index > array.len() - 1 {
        return None;
    }

    let mut loop_index = 1;

    if from_index > 0 {
        loop_index = from_index;
    }

    for index in 0..loop_index {
        let value = array[from_index - index];
        if f(value) {
            return Some(value);
        }
    }

    None
}

#[test]
fn test_new() {
    assert_eq!(new([1, 2, 3, 4].to_vec(), &|x: i32| x < 3, 3), Some(2));
    assert_eq!(new([1, 2, 3, 4].to_vec(), &|x: i32| x % 2 == 1, 3), Some(3));
    assert_eq!(new([1, 2, 3, 4].to_vec(), &|x: i32| x < 3, 5), None);
    assert_eq!(new([1, 2, 3, 4].to_vec(), &|x: i32| x == 1, 0), Some(1));
}