iter.reduce(fn) =============== [

](https://github.com/dtolnay/reduce) [

](https://crates.io/crates/reduce) [

](https://docs.rs/reduce) [

](https://github.com/dtolnay/reduce/actions?query=branch%3Amaster) This crate gives Iterators a `reduce` function that is similar to [`fold`][std-fold] but without an initial value. The function returns `None` if the iterator is empty and `Some(value)` otherwise. This matches the distinction between [`reduce`][scala-reduce] and [`fold`][scala-fold] in Scala. [std-fold]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.fold [scala-reduce]: https://www.scala-lang.org/api/current/scala/collection/Iterator.html#reduce[A1%3E:A](op:(A1,A1)=%3EA1):A1 [scala-fold]: https://www.scala-lang.org/api/current/scala/collection/Iterator.html#fold[A1%3E:A](z:A1)(op:(A1,A1)=%3EA1):A1 ```toml [dependencies] reduce = "0.1" ``` ## Examples ```rust use reduce::Reduce; fn main() { // Reduce a non-empty iterator into Some(value) let v = vec![1usize, 2, 3, 4, 5]; let sum = v.into_iter().reduce(|a, b| a + b); assert_eq!(Some(15), sum); // Reduce an empty iterator into None let v = Vec::::new(); let sum = v.into_iter().reduce(|a, b| a + b); assert_eq!(None, sum); } ```
#### License ^{Licensed under either of Apache License, Version
2.0 or MIT license at your option.}
_{Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
be dual licensed as above, without any additional terms or conditions.}