Iterator Structs

Iterator adapter และ helper structs

Common Iterator Adapters

fn main() {
    let v = vec![1, 2, 3, 4, 5];

    // Map - transform each element
    let mapped: Vec<_> = v.iter().map(|x| x * 2).collect();
    println!("Map: {:?}", mapped);

    // Filter - keep matching elements
    let filtered: Vec<_> = v.iter().filter(|&&x| x > 2).collect();
    println!("Filter: {:?}", filtered);

    // FilterMap - filter and map combined
    let filter_mapped: Vec<_> = v.iter()
        .filter_map(|&x| if x > 2 { Some(x * 10) } else { None })
        .collect();
    println!("FilterMap: {:?}", filter_mapped);

    // Take - first n elements
    let taken: Vec<_> = v.iter().take(3).collect();
    println!("Take 3: {:?}", taken);

    // Skip - skip first n
    let skipped: Vec<_> = v.iter().skip(2).collect();
    println!("Skip 2: {:?}", skipped);

    // TakeWhile / SkipWhile
    let take_while: Vec<_> = v.iter().take_while(|&&x| x < 4).collect();
    println!("TakeWhile < 4: {:?}", take_while);

    // StepBy - every nth element
    let stepped: Vec<_> = v.iter().step_by(2).collect();
    println!("StepBy 2: {:?}", stepped);
}