Trait spans::Spans

pub trait Spans: Iterator {
    pub fn spans_by_key<K, C, F>(
        self, 
        key: K, 
        are_connected: F
    ) -> SpansBy<Self, K, F>
    where
        K: Fn(&Self::Item) -> C,
        C: Copy,
        F: Fn(C, C) -> bool,
        Self: Sized,
    { ... }
}

Spans provides an iterator adapter for SpansBy.

Provided methods

pub fn spans_by_key<K, C, F>(
    self,
    key: K,
    are_connected: F
) -> SpansBy<Self, K, F> where
    K: Fn(&Self::Item) -> C,
    C: Copy,
    F: Fn(C, C) -> bool,
    Self: Sized, 

Splits the iterator into contiguous spans.

are_connected returns true if the two given adjacent items are part of the same span, false otherwise. Items are not compared directly; instead, a key is made for each item using the key function. are_connected is given the key of the previous item and the key of the current item.

Examples

Create spans for items increasing in value by 1:

use spans::Spans;

let vec = vec![1, 2, 5, 6, 7, 11, 13, 14, 15];
let mut spans = vec.iter().spans_by_key(|&&x| x, |a, b| a + 1 == b);

assert_eq!(spans.next().unwrap().collect::<Vec<_>>(), vec![&1, &2]);
assert_eq!(spans.next().unwrap().collect::<Vec<_>>(), vec![&5, &6, &7]);
assert_eq!(spans.next().unwrap().collect::<Vec<_>>(), vec![&11]);
assert_eq!(spans.next().unwrap().collect::<Vec<_>>(), vec![&13, &14, &15]);
assert!(spans.next().is_none());

Create spans for strings of the same length:

use spans::Spans;

let vec = vec!["abc", "run", "tag", "go", "be", "ring", "zip", "zap", "put"];
let mut spans = vec.iter().spans_by_key(|x| x.len(), |a, b| a == b);

assert_eq!(
    spans.next().unwrap().collect::<Vec<_>>(),
    vec![&"abc", &"run", &"tag"]
);
assert_eq!(
    spans.next().unwrap().collect::<Vec<_>>(),
    vec![&"go", &"be"]
);
assert_eq!(
    spans.next().unwrap().collect::<Vec<_>>(),
    vec![&"ring"]
);
assert_eq!(
    spans.next().unwrap().collect::<Vec<_>>(),
    vec![&"zip", &"zap", &"put"]
);
assert!(spans.next().is_none());

Loading content...

Implementors

impl<I: Iterator> Spans for I

Loading content...