Struct textwrap::word_separators::UnicodeBreakProperties

pub struct UnicodeBreakProperties;

Find words using the Unicode line breaking algorithm.

Trait Implementations

impl Clone for UnicodeBreakProperties

fn clone(&self) -> UnicodeBreakProperties

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for UnicodeBreakProperties

impl Debug for UnicodeBreakProperties

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for UnicodeBreakProperties

fn default() -> UnicodeBreakProperties

Returns the "default value" for a type.

impl WordSeparator for UnicodeBreakProperties

Split line into words using Unicode break properties.

This word separator uses the Unicode line breaking algorithm described in Unicode Standard Annex #14 to find legal places to break lines. There is a small difference in that the U+002D (Hyphen-Minus) and U+00AD (Soft Hyphen) don’t create a line break: to allow a line break at a hyphen, use the HyphenSplitter. Soft hyphens are not currently supported.

Examples

Unlike AsciiSpace, the Unicode line breaking algorithm will find line break opportunities between some characters with no intervening whitespace:

#[cfg(feature = "unicode-linebreak")] {
use textwrap::word_separators::{WordSeparator, UnicodeBreakProperties};
use textwrap::core::Word;

assert_eq!(UnicodeBreakProperties.find_words("Emojis: 😂😍").collect::<Vec<_>>(),
           vec![Word::from("Emojis: "),
                Word::from("😂"),
                Word::from("😍")]);

assert_eq!(UnicodeBreakProperties.find_words("CJK: 你好").collect::<Vec<_>>(),
           vec![Word::from("CJK: "),
                Word::from("你"),
                Word::from("好")]);
}

A U+2060 (Word Joiner) character can be inserted if you want to manually override the defaults and keep the characters together:

#[cfg(feature = "unicode-linebreak")] {
use textwrap::word_separators::{UnicodeBreakProperties, WordSeparator};
use textwrap::core::Word;

assert_eq!(UnicodeBreakProperties.find_words("Emojis: 😂\u{2060}😍").collect::<Vec<_>>(),
           vec![Word::from("Emojis: "),
                Word::from("😂\u{2060}😍")]);
}

The Unicode line breaking algorithm will also automatically suppress break breaks around certain punctuation characters::

#[cfg(feature = "unicode-linebreak")] {
use textwrap::word_separators::{UnicodeBreakProperties, WordSeparator};
use textwrap::core::Word;

assert_eq!(UnicodeBreakProperties.find_words("[ foo ] bar !").collect::<Vec<_>>(),
           vec![Word::from("[ foo ] "),
                Word::from("bar !")]);
}

fn find_words<'a>(
    &self,
    line: &'a str
) -> Box<dyn Iterator<Item = Word<'a>> + 'a>

Find all words in line.