1 use Itertools;
2
3 /// Combine all an iterator's elements into one element by using `Extend`.
4 ///
5 /// `IntoIterator`-enabled version of `.concat()`
6 ///
7 /// This combinator will extend the first item with each of the rest of the
8 /// items of the iterator. If the iterator is empty, the default value of
9 /// `I::Item` is returned.
10 ///
11 /// ```rust
12 /// use itertools::concat;
13 ///
14 /// let input = vec![vec![1], vec![2, 3], vec![4, 5, 6]];
15 /// assert_eq!(concat(input), vec![1, 2, 3, 4, 5, 6]);
16 /// ```
concat<I>(iterable: I) -> I::Item where I: IntoIterator, I::Item: Extend<<<I as IntoIterator>::Item as IntoIterator>::Item> + IntoIterator + Default17 pub fn concat<I>(iterable: I) -> I::Item
18 where I: IntoIterator,
19 I::Item: Extend<<<I as IntoIterator>::Item as IntoIterator>::Item> + IntoIterator + Default
20 {
21 iterable.into_iter().fold1(|mut a, b| { a.extend(b); a }).unwrap_or_else(|| <_>::default())
22 }
23