https://github.com/dtolnay/reduce

iter.reduce(fn) in Rust
https://github.com/dtolnay/reduce

iterator rust

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iter.reduce(fn) in Rust

• Host: GitHub
• URL: https://github.com/dtolnay/reduce
• Owner: dtolnay
• License: apache-2.0
• Archived: true
• Created: 2016-06-19T22:26:43.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2022-12-19T18:35:43.000Z (almost 2 years ago)
• Last Synced: 2024-11-16T18:46:17.770Z (4 days ago)
• Topics: iterator, rust
• Language: Rust
• Homepage:
• Size: 68.4 KB
• Stars: 36
• Watchers: 3
• Forks: 0
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE-APACHE

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README

        
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.