Struct BidiInfo

pub struct BidiInfo<'text> {
    pub text: &'text str,
    pub original_classes: Vec<BidiClass>,
    pub levels: Vec<Level>,
    pub paragraphs: Vec<ParagraphInfo>,
}

Bidi information of the text

The original_classes and levels vectors are indexed by byte offsets into the text. If a character is multiple bytes wide, then its class and level will appear multiple times in these vectors.

Fields

text: &'text str

The text

original_classes: Vec<BidiClass>

The BidiClass of the character at each byte in the text.

levels: Vec<Level>

The directional embedding level of each byte in the text.

paragraphs: Vec<ParagraphInfo>

The boundaries and paragraph embedding level of each paragraph within the text.

TODO: Use SmallVec or similar to avoid overhead when there are only one or two paragraphs? Or just don’t include the first paragraph, which always starts at 0?

Implementations

impl<'text> BidiInfo<'text>

pub fn new(text: &str, default_para_level: Option<Level>) -> BidiInfo<'_>

Split the text into paragraphs and determine the bidi embedding levels for each paragraph.

TODO: In early steps, check for special cases that allow later steps to be skipped. like text that is entirely LTR. See the nsBidi class from Gecko for comparison.

TODO: Support auto-RTL base direction

pub fn reordered_levels( &self, para: &ParagraphInfo, line: Range<usize>, ) -> Vec<Level>

Re-order a line based on resolved levels and return only the embedding levels, one Level per byte.

pub fn reordered_levels_per_char( &self, para: &ParagraphInfo, line: Range<usize>, ) -> Vec<Level>

Re-order a line based on resolved levels and return only the embedding levels, one Level per character.

pub fn reorder_line( &self, para: &ParagraphInfo, line: Range<usize>, ) -> Cow<'text, str>

Re-order a line based on resolved levels and return the line in display order.

pub fn visual_runs( &self, para: &ParagraphInfo, line: Range<usize>, ) -> (Vec<Level>, Vec<LevelRun>)

Find the level runs within a line and return them in visual order.

line is a range of bytes indices within levels.

https://www.unicode.org/reports/tr9/#Reordering_Resolved_Levels

pub fn has_rtl(&self) -> bool

If processed text has any computed RTL levels

This information is usually used to skip re-ordering of text when no RTL level is present

Trait Implementations

impl<'text> Debug for BidiInfo<'text>

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

Formats the value using the given formatter.

impl<'text> Display for BidiInfo<'text>

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

Formats the value using the given formatter.

impl<'text> Hash for BidiInfo<'text>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'text> PartialEq for BidiInfo<'text>

fn eq(&self, other: &BidiInfo<'text>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'text> Eq for BidiInfo<'text>

impl<'text> StructuralPartialEq for BidiInfo<'text>