Iterators which split strings on Grapheme Cluster or Word boundaries, according to the Unicode Standard Annex #29 rules.

Documentation
use unicode_segmentation::UnicodeSegmentation;
fn main() {
    let s = "a̐éö̲\r\n";
    let g = s.graphemes(true).collect::<Vec<&str>>();
    let b: &[_] = &["a̐", "é", "ö̲", "\r\n"];
    assert_eq!(g, b);
    let s = "The quick (\"brown\") fox can't jump 32.3 feet, right?";
    let w = s.unicode_words().collect::<Vec<&str>>();
    let b: &[_] = &["The", "quick", "brown", "fox", "can't", "jump", "32.3", "feet", "right"];
    assert_eq!(w, b);
    let s = "The quick (\"brown\")  fox";
    let w = s.split_word_bounds().collect::<Vec<&str>>();
    let b: &[_] = &["The", " ", "quick", " ", "(", "\"", "brown", "\"", ")", "  ", "fox"];
    assert_eq!(w, b);
}
no_std
unicode-segmentation does not depend on libstd, so it can be used in crates with the #![no_std] attribute.
crates.io
You can use this package in your project by adding the following to your Cargo.toml:
[dependencies]
unicode-segmentation = "1.10.1"
Change Log
1.11.0
- #124 Update data to Unicode 15.1
- #128 Add size_hintto iterators
1.10.1
- #113 Use criterion.rs for word benchmarks
- #112 Improve table search speed through lookups
1.10.0
- #107 Upgrade to Unicode 15.0.0
- #104 Supersedes and fixes #75
1.9.0
- #101 Upgrade to Unicode 14.0.0
1.8.0
- #100 * #100 - Increase #[inline]opportunities, resulting in 15-40% performance improvement.
- #95 Implement debug for Graphemes
- #94 Add Initial fuzzer for oss-fuzz integration
- #93 Fix  unused imports and deprecated pattern warnings
- #91 Made local variable immutable by moving it into loop
- #91 Add new iterator UnicodeWordIndices and unicode_word_indices
1.7.1
- Update docs on version number
1.7.0
- #87 Upgrade to Unicode 13
- #79 Implement a special-case lookup for ascii grapheme categories
- #77 Optimization for grapheme iteration
1.6.0
- #72 Upgrade to Unicode 12
1.5.0
- #68 Upgrade to Unicode 11
1.4.0
- #56 Upgrade to Unicode 10
1.3.0
- #24 Add support for sentence boundaries
- #44 Treat gc=Noas a subset ofgc=N
1.2.1
- #37: Fix panic in provide_context.
- #40: Fix crash in prev_boundary.
1.2.0
- New GraphemeCursorAPI allows random access and bidirectional iteration.
- Fixed incorrect splitting of certain emoji modifier sequences.
1.1.0
- Add as_strmethods to the iterator types.
1.0.3
- Code cleanup and additional tests.
1.0.1
- Fix a bug affecting some grapheme clusters containing Prepend characters.
1.0.0
- Upgrade to Unicode 9.0.0.