Quelle lib.rs
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// Copyright 2015 The Servo Project Developers. See the
// COPYRIGHT file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! This crate implements the [Unicode Bidirectional Algorithm][tr9] for display of mixed
//! right-to-left and left-to-right text. It is written in safe Rust, compatible with the
//! current stable release.
//!
//! ## Example
//!
//! ```rust
//! # #[cfg(feature = "hardcoded-data")] {
//! use unicode_bidi::BidiInfo;
//!
//! // This example text is defined using `concat!` because some browsers
//! // and text editors have trouble displaying bidi strings.
//! let text = concat![
//! "א",
//! "ב",
//! "ג",
//! "a",
//! "b",
//! "c",
//! ];
//!
//! // Resolve embedding levels within the text. Pass `None` to detect the
//! // paragraph level automatically.
//! let bidi_info = BidiInfo::new(&text, None);
//!
//! // This paragraph has embedding level 1 because its first strong character is RTL.
//! assert_eq!(bidi_info.paragraphs.len(), 1);
//! let para = &bidi_info.paragraphs[0];
//! assert_eq!(para.level.number(), 1);
//! assert_eq!(para.level.is_rtl(), true);
//!
//! // Re-ordering is done after wrapping each paragraph into a sequence of
//! // lines. For this example, I'll just use a single line that spans the
//! // entire paragraph.
//! let line = para.range.clone();
//!
//! let display = bidi_info.reorder_line(para, line);
//! assert_eq!(display, concat![
//! "a",
//! "b",
//! "c",
//! "ג",
//! "ב",
//! "א",
//! ]);
//! # } // feature = "hardcoded-data"
//! ```
//!
//! # Features
//!
//! - `std`: Enabled by default, but can be disabled to make `unicode_bidi`
//! `#![no_std]` + `alloc` compatible.
//! - `hardcoded-data`: Enabled by default. Includes hardcoded Unicode bidi data and more con venient APIs.
//! - `serde`: Adds [`serde::Serialize`] and [`serde::Deserialize`]
//! implementations to relevant types.
//!
//! [tr9]: <http://www.unicode.org/reports/tr9/>
#![no_std]
// We need to link to std to make doc tests work on older Rust versions
#[cfg(feature = "std")]
extern crate std;
#[macro_use]
extern crate alloc;
#[cfg(feature = "smallvec")]
extern crate smallvec;
pub mod data_source;
pub mod deprecated;
pub mod format_chars;
pub mod level;
pub mod utf16;
mod char_data;
mod explicit;
mod implicit;
mod prepare;
pub use crate::char_data::{BidiClass, UNICODE_VERSION};
pub use crate::data_source::BidiDataSource;
pub use crate::level::{Level, LTR_LEVEL, RTL_LEVEL};
pub use crate::prepare::{LevelRun, LevelRunVec};
#[cfg(feature = "hardcoded-data")]
pub use crate::char_data::{bidi_class, HardcodedBidiData};
use alloc::borrow::Cow;
use alloc::string::String;
use alloc::vec::Vec;
use core::char;
use core::cmp;
use core::iter::repeat;
use core::ops::Range;
use core::str::CharIndices;
#[cfg(feature = "smallvec")]
use smallvec::SmallVec;
use crate::format_chars as chars;
use crate::BidiClass::*;
/// Trait that abstracts over a text source for use by the bidi algorithms.
/// We implement this for str (UTF-8) and for [u16] (UTF-16, native-endian).
/// (For internal unicode-bidi use; API may be unstable.)
/// This trait is sealed and cannot be implemented for types outside this crate.
pub trait TextSource<'text>: private::Sealed {
type CharIter: Iterator<Item = char>;
type CharIndexIter: Iterator<Item = (usize, char)>;
type IndexLenIter: Iterator<Item = (usize, usize)>;
/// Return the length of the text in code units.
#[doc(hidden)]
fn len(&self) -> usize;
/// Get the character at a given code unit index, along with its length in code units.
/// Returns None if index is out of range, or points inside a multi-code-unit character.
/// Returns REPLACEMENT_CHARACTER for any unpaired surrogates in UTF-16.
#[doc(hidden)]
fn char_at(&self, index: usize) -> Option<(char, usize)>;
/// Return a subrange of the text, indexed by code units.
/// (We don't implement all of the Index trait, just the minimum we use.)
#[doc(hidden)]
fn subrange(&self, range: Range<usize>) -> &Self;
/// An iterator over the text returning Unicode characters,
/// REPLACEMENT_CHAR for invalid code units.
#[doc(hidden)]
fn chars(&'text self) -> Self::CharIter;
/// An iterator over the text returning (index, char) tuples,
/// where index is the starting code-unit index of the character,
/// and char is its Unicode value (or REPLACEMENT_CHAR if invalid).
#[doc(hidden)]
fn char_indices(&'text self) -> Self::CharIndexIter;
/// An iterator over the text returning (index, length) tuples,
/// where index is the starting code-unit index of the character,
/// and length is its length in code units.
#[doc(hidden)]
fn indices_lengths(&'text self) -> Self::IndexLenIter;
/// Number of code units the given character uses.
#[doc(hidden)]
fn char_len(ch: char) -> usize;
}
mod private {
pub trait Sealed {}
// Implement for str and [u16] only.
impl Sealed for str {}
impl Sealed for [u16] {}
}
#[derive(PartialEq, Debug)]
pub enum Direction {
Ltr,
Rtl,
Mixed,
}
/// Bidi information about a single paragraph
#[derive(Clone, Debug, PartialEq)]
pub struct ParagraphInfo {
/// The paragraphs boundaries within the text, as byte indices.
///
/// TODO: Shrink this to only include the starting index?
pub range: Range<usize>,
/// The paragraph embedding level.
///
/// <http://www.unicode.org/reports/tr9/#BD4>
pub level: Level,
}
impl ParagraphInfo {
/// Gets the length of the paragraph in the source text.
pub fn len(&self) -> usize {
self.range.end - self.range.start
}
}
/// Initial bidi information of the text.
///
/// Contains the text paragraphs and `BidiClass` of its characters.
#[derive(PartialEq, Debug)]
pub struct InitialInfo<'text> {
/// The text
pub text: &'text str,
/// The BidiClass of the character at each byte in the text.
/// If a character is multiple bytes, its class will appear multiple times in the vector.
pub original_classes: Vec<BidiClass>,
/// The boundaries and level of each paragraph within the text.
pub paragraphs: Vec<ParagraphInfo>,
}
impl<'text> InitialInfo<'text> {
/// Find the paragraphs and BidiClasses in a string of text.
///
/// <http://www.unicode.org/reports/tr9/#The_Paragraph_Level>
///
/// Also sets the class for each First Strong Isolate initiator (FSI) to LRI or RLI if a strong
/// character is found before the matching PDI. If no strong character is found, the class will
/// remain FSI, and it's up to later stages to treat these as LRI when needed.
///
/// The `hardcoded-data` Cargo feature (enabled by default) must be enabled to use this.
#[cfg_attr(feature = "flame_it", flamer::flame)]
#[cfg(feature = "hardcoded-data")]
pub fn new(text: &str, default_para_level: Option<Level>) -> InitialInfo<'_> {
Self::new_with_data_source(&HardcodedBidiData, text, default_para_level)
}
/// Find the paragraphs and BidiClasses in a string of text, with a custom [`BidiDataSource`]
/// for Bidi data. If you just wish to use the hardcoded Bidi data, please use [`InitialInfo::new()`]
/// instead (enabled with tbe default `hardcoded-data` Cargo feature)
///
/// <http://www.unicode.org/reports/tr9/#The_Paragraph_Level>
///
/// Also sets the class for each First Strong Isolate initiator (FSI) to LRI or RLI if a strong
/// character is found before the matching PDI. If no strong character is found, the class will
/// remain FSI, and it's up to later stages to treat these as LRI when needed.
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn new_with_data_source<'a, D: BidiDataSource>(
data_source: &D,
text: &'a str,
default_para_level: Option<Level>,
) -> InitialInfo<'a> {
InitialInfoExt::new_with_data_source(data_source, text, default_para_level).base
}
}
/// Extended version of InitialInfo (not public API).
#[derive(PartialEq, Debug)]
struct InitialInfoExt<'text> {
/// The base InitialInfo for the text, recording its paragraphs and bidi classes.
base: InitialInfo<'text>,
/// Parallel to base.paragraphs, records whether each paragraph is "pure LTR" that
/// requires no further bidi processing (i.e. there are no RTL characters or bidi
/// control codes present), and whether any bidi isolation controls are present.
flags: Vec<ParagraphInfoFlags>,
}
#[derive(PartialEq, Debug)]
struct ParagraphInfoFlags {
is_pure_ltr: bool,
has_isolate_controls: bool,
}
impl<'text> InitialInfoExt<'text> {
/// Find the paragraphs and BidiClasses in a string of text, with a custom [`BidiDataSource`]
/// for Bidi data. If you just wish to use the hardcoded Bidi data, please use [`InitialInfo::new()`]
/// instead (enabled with tbe default `hardcoded-data` Cargo feature)
///
/// <http://www.unicode.org/reports/tr9/#The_Paragraph_Level>
///
/// Also sets the class for each First Strong Isolate initiator (FSI) to LRI or RLI if a strong
/// character is found before the matching PDI. If no strong character is found, the class will
/// remain FSI, and it's up to later stages to treat these as LRI when needed.
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn new_with_data_source<'a, D: BidiDataSource>(
data_source: &D,
text: &'a str,
default_para_level: Option<Level>,
) -> InitialInfoExt<'a> {
let mut paragraphs = Vec::<ParagraphInfo>::new();
let mut flags = Vec::<ParagraphInfoFlags>::new();
let (original_classes, _, _, _) = compute_initial_info(
data_source,
text,
default_para_level,
Some((&mut paragraphs, &mut flags)),
);
InitialInfoExt {
base: InitialInfo {
text,
original_classes,
paragraphs,
},
flags,
}
}
}
/// Implementation of initial-info computation for both BidiInfo and ParagraphBidiInfo.
/// To treat the text as (potentially) multiple paragraphs, the caller should pass the
/// pair of optional outparam arrays to receive the ParagraphInfo and pure-ltr flags
/// for each paragraph. Passing None for split_paragraphs will ignore any paragraph-
/// separator characters in the text, treating it just as a single paragraph.
/// Returns the array of BidiClass values for each code unit of the text, along with
/// the embedding level and pure-ltr flag for the *last* (or only) paragraph.
fn compute_initial_info<'a, D: BidiDataSource, T: TextSource<'a> + ?Sized>(
data_source: &D,
text: &'a T,
default_para_level: Option<Level>,
mut split_paragraphs: Option<(&mut Vec<ParagraphInfo>, &mut Vec<ParagraphInfoFlags>)>,
) -> (Vec<BidiClass>, Level, bool, bool) {
let mut original_classes = Vec::with_capacity(text.len());
// The stack contains the starting code unit index for each nested isolate we're inside.
#[cfg(feature = "smallvec")]
let mut isolate_stack = SmallVec::<[usize; 8]>::new();
#[cfg(not(feature = "smallvec"))]
let mut isolate_stack = Vec::new();
debug_assert!(
if let Some((ref paragraphs, ref flags)) = split_paragraphs {
paragraphs.is_empty() && flags.is_empty()
} else {
true
}
);
let mut para_start = 0;
let mut para_level = default_para_level;
// Per-paragraph flag: can subsequent processing be skipped? Set to false if any
// RTL characters or bidi control characters are encountered in the paragraph.
let mut is_pure_ltr = true;
// Set to true if any bidi isolation controls are present in the paragraph.
let mut has_isolate_controls = false;
#[cfg(feature = "flame_it")]
flame::start("compute_initial_info(): iter text.char_indices()");
for (i, c) in text.char_indices() {
let class = data_source.bidi_class(c);
#[cfg(feature = "flame_it")]
flame::start("original_classes.extend()");
let len = T::char_len(c);
original_classes.extend(repeat(class).take(len));
#[cfg(feature = "flame_it")]
flame::end("original_classes.extend()");
match class {
B => {
if let Some((ref mut paragraphs, ref mut flags)) = split_paragraphs {
// P1. Split the text into separate paragraphs. The paragraph separator is kept
// with the previous paragraph.
let para_end = i + len;
paragraphs.push(ParagraphInfo {
range: para_start..para_end,
// P3. If no character is found in p2, set the paragraph level to zero.
level: para_level.unwrap_or(LTR_LEVEL),
});
flags.push(ParagraphInfoFlags {
is_pure_ltr,
has_isolate_controls,
});
// Reset state for the start of the next paragraph.
para_start = para_end;
// TODO: Support defaulting to direction of previous paragraph
//
// <http://www.unicode.org/reports/tr9/#HL1>
para_level = default_para_level;
is_pure_ltr = true;
has_isolate_controls = false;
isolate_stack.clear();
}
}
L | R | AL => {
if class != L {
is_pure_ltr = false;
}
match isolate_stack.last() {
Some(&start) => {
if original_classes[start] == FSI {
// X5c. If the first strong character between FSI and its matching
// PDI is R or AL, treat it as RLI. Otherwise, treat it as LRI.
for j in 0..T::char_len(chars::FSI) {
original_classes[start + j] = if class == L { LRI } else { RLI };
}
}
}
None => {
if para_level.is_none() {
// P2. Find the first character of type L, AL, or R, while skipping
// any characters between an isolate initiator and its matching
// PDI.
para_level = Some(if class != L { RTL_LEVEL } else { LTR_LEVEL });
}
}
}
}
AN | LRE | RLE | LRO | RLO => {
is_pure_ltr = false;
}
RLI | LRI | FSI => {
is_pure_ltr = false;
has_isolate_controls = true;
isolate_stack.push(i);
}
PDI => {
isolate_stack.pop();
}
_ => {}
}
}
if let Some((paragraphs, flags)) = split_paragraphs {
if para_start < text.len() {
paragraphs.push(ParagraphInfo {
range: para_start..text.len(),
level: para_level.unwrap_or(LTR_LEVEL),
});
flags.push(ParagraphInfoFlags {
is_pure_ltr,
has_isolate_controls,
});
}
debug_assert_eq!(paragraphs.len(), flags.len());
}
debug_assert_eq!(original_classes.len(), text.len());
#[cfg(feature = "flame_it")]
flame::end("compute_initial_info(): iter text.char_indices()");
(
original_classes,
para_level.unwrap_or(LTR_LEVEL),
is_pure_ltr,
has_isolate_controls,
)
}
/// 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.
// TODO: Impl `struct StringProperty<T> { values: Vec<T> }` and use instead of Vec<T>
#[derive(Debug, PartialEq)]
pub struct BidiInfo<'text> {
/// The text
pub text: &'text str,
/// The BidiClass of the character at each byte in the text.
pub original_classes: Vec<BidiClass>,
/// The directional embedding level of each byte in the text.
pub levels: Vec<Level>,
/// 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?
pub paragraphs: Vec<ParagraphInfo>,
}
impl<'text> BidiInfo<'text> {
/// Split the text into paragraphs and determine the bidi embedding levels for each paragraph.
///
///
/// The `hardcoded-data` Cargo feature (enabled by default) must be enabled to use this.
///
/// 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
#[cfg_attr(feature = "flame_it", flamer::flame)]
#[cfg(feature = "hardcoded-data")]
#[inline]
pub fn new(text: &str, default_para_level: Option<Level>) -> BidiInfo<'_> {
Self::new_with_data_source(&HardcodedBidiData, text, default_para_level)
}
/// Split the text into paragraphs and determine the bidi embedding levels for each paragraph, with a custom [`BidiDataSource`]
/// for Bidi data. If you just wish to use the hardcoded Bidi data, please use [`BidiInfo::new()`]
/// instead (enabled with tbe default `hardcoded-data` Cargo feature).
///
/// 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
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn new_with_data_source<'a, D: BidiDataSource>(
data_source: &D,
text: &'a str,
default_para_level: Option<Level>,
) -> BidiInfo<'a> {
let InitialInfoExt { base, flags, .. } =
InitialInfoExt::new_with_data_source(data_source, text, default_para_level);
let mut levels = Vec::<Level>::with_capacity(text.len());
let mut processing_classes = base.original_classes.clone();
for (para, flags) in base.paragraphs.iter().zip(flags.iter()) {
let text = &text[para.range.clone()];
let original_classes = &base.original_classes[para.range.clone()];
compute_bidi_info_for_para(
data_source,
para,
flags.is_pure_ltr,
flags.has_isolate_controls,
text,
original_classes,
&mut processing_classes,
&mut levels,
);
}
BidiInfo {
text,
original_classes: base.original_classes,
paragraphs: base.paragraphs,
levels,
}
}
/// Produce the levels for this paragraph as needed for reordering, one level per *byte*
/// in the paragraph. The returned vector includes bytes that are not included
/// in the `line`, but will not adjust them.
///
/// This runs [Rule L1], you can run
/// [Rule L2] by calling [`Self::reorder_visual()`].
/// If doing so, you may prefer to use [`Self::reordered_levels_per_char()`] instead
/// to avoid non-byte indices.
///
/// For an all-in-one reordering solution, consider using [`Self::reorder_visual()`].
///
/// [Rule L1]: https://www.unicode.org/reports/tr9/#L1
/// [Rule L2]: https://www.unicode.org/reports/tr9/#L2
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn reordered_levels(&self, para: &ParagraphInfo, line: Range<usize>) -> Vec<Level> {
assert!(line.start <= self.levels.len());
assert!(line.end <= self.levels.len());
let mut levels = self.levels.clone();
let line_classes = &self.original_classes[line.clone()];
let line_levels = &mut levels[line.clone()];
reorder_levels(
line_classes,
line_levels,
self.text.subrange(line),
para.level,
);
levels
}
/// Produce the levels for this paragraph as needed for reordering, one level per *character*
/// in the paragraph. The returned vector includes characters that are not included
/// in the `line`, but will not adjust them.
///
/// This runs [Rule L1], you can run
/// [Rule L2] by calling [`Self::reorder_visual()`].
/// If doing so, you may prefer to use [`Self::reordered_levels_per_char()`] instead
/// to avoid non-byte indices.
///
/// For an all-in-one reordering solution, consider using [`Self::reorder_visual()`].
///
/// [Rule L1]: https://www.unicode.org/reports/tr9/#L1
/// [Rule L2]: https://www.unicode.org/reports/tr9/#L2
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn reordered_levels_per_char(
&self,
para: &ParagraphInfo,
line: Range<usize>,
) -> Vec<Level> {
let levels = self.reordered_levels(para, line);
self.text.char_indices().map(|(i, _)| levels[i]).collect()
}
/// Re-order a line based on resolved levels and return the line in display order.
///
/// This does not apply [Rule L3] or [Rule L4] around combining characters or mirroring.
///
/// [Rule L3]: https://www.unicode.org/reports/tr9/#L3
/// [Rule L4]: https://www.unicode.org/reports/tr9/#L4
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn reorder_line(&self, para: &ParagraphInfo, line: Range<usize>) -> Cow<'text, str> {
if !level::has_rtl(&self.levels[line.clone()]) {
return self.text[line].into();
}
let (levels, runs) = self.visual_runs(para, line.clone());
reorder_line(self.text, line, levels, runs)
}
/// Reorders pre-calculated levels of a sequence of characters.
///
/// NOTE: This is a convenience method that does not use a `Paragraph` object. It is
/// intended to be used when an application has determined the levels of the objects (character sequences)
/// and just needs to have them reordered.
///
/// the index map will result in `indexMap[visualIndex]==logicalIndex`.
///
/// This only runs [Rule L2](http://www.unicode.org/reports/tr9/#L2) as it does not have
/// information about the actual text.
///
/// Furthermore, if `levels` is an array that is aligned with code units, bytes within a codepoint may be
/// reversed. You may need to fix up the map to deal with this. Alternatively, only pass in arrays where each `Level`
/// is for a single code point.
///
///
/// # # Example
/// ```
/// use unicode_bidi::BidiInfo;
/// use unicode_bidi::Level;
///
/// let l0 = Level::from(0);
/// let l1 = Level::from(1);
/// let l2 = Level::from(2);
///
/// let levels = vec![l0, l0, l0, l0];
/// let index_map = BidiInfo::reorder_visual(&levels);
/// assert_eq!(levels.len(), index_map.len());
/// assert_eq!(index_map, [0, 1, 2, 3]);
///
/// let levels: Vec<Level> = vec![l0, l0, l0, l1, l1, l1, l2, l2];
/// let index_map = BidiInfo::reorder_visual(&levels);
/// assert_eq!(levels.len(), index_map.len());
/// assert_eq!(index_map, [0, 1, 2, 6, 7, 5, 4, 3]);
/// ```
#[cfg_attr(feature = "flame_it", flamer::flame)]
#[inline]
pub fn reorder_visual(levels: &[Level]) -> Vec<usize> {
reorder_visual(levels)
}
/// Find the level runs within a line and return them in visual order.
///
/// `line` is a range of bytes indices within `levels`.
///
/// The first return value is a vector of levels used by the reordering algorithm,
/// i.e. the result of [Rule L1]. The second return value is a vector of level runs,
/// the result of [Rule L2], showing the visual order that each level run (a run of text with the
/// same level) should be displayed. Within each run, the display order can be checked
/// against the Level vector.
///
/// This does not handle [Rule L3] (combining characters) or [Rule L4] (mirroring),
/// as that should be handled by the engine using this API.
///
/// Conceptually, this is the same as running [`Self::reordered_levels()`] followed by
/// [`Self::reorder_visual()`], however it returns the result as a list of level runs instead
/// of producing a level map, since one may wish to deal with the fact that this is operating on
/// byte rather than character indices.
///
/// <http://www.unicode.org/reports/tr9/#Reordering_Resolved_Levels>
///
/// [Rule L1]: https://www.unicode.org/reports/tr9/#L1
/// [Rule L2]: https://www.unicode.org/reports/tr9/#L2
/// [Rule L3]: https://www.unicode.org/reports/tr9/#L3
/// [Rule L4]: https://www.unicode.org/reports/tr9/#L4
#[cfg_attr(feature = "flame_it", flamer::flame)]
#[inline]
pub fn visual_runs(
&self,
para: &ParagraphInfo,
line: Range<usize>,
) -> (Vec<Level>, Vec<LevelRun>) {
let levels = self.reordered_levels(para, line.clone());
visual_runs_for_line(levels, &line)
}
/// 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
#[inline]
pub fn has_rtl(&self) -> bool {
level::has_rtl(&self.levels)
}
}
/// Bidi information of text treated as a single paragraph.
///
/// 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.
#[derive(Debug, PartialEq)]
pub struct ParagraphBidiInfo<'text> {
/// The text
pub text: &'text str,
/// The BidiClass of the character at each byte in the text.
pub original_classes: Vec<BidiClass>,
/// The directional embedding level of each byte in the text.
pub levels: Vec<Level>,
/// The paragraph embedding level.
pub paragraph_level: Level,
/// Whether the paragraph is purely LTR.
pub is_pure_ltr: bool,
}
impl<'text> ParagraphBidiInfo<'text> {
/// Determine the bidi embedding level.
///
///
/// The `hardcoded-data` Cargo feature (enabled by default) must be enabled to use this.
///
/// 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
#[cfg_attr(feature = "flame_it", flamer::flame)]
#[cfg(feature = "hardcoded-data")]
#[inline]
pub fn new(text: &str, default_para_level: Option<Level>) -> ParagraphBidiInfo<'_> {
Self::new_with_data_source(&HardcodedBidiData, text, default_para_level)
}
/// Determine the bidi embedding level, with a custom [`BidiDataSource`]
/// for Bidi data. If you just wish to use the hardcoded Bidi data, please use [`BidiInfo::new()`]
/// instead (enabled with tbe default `hardcoded-data` Cargo feature).
///
/// (This is the single-paragraph equivalent of BidiInfo::new_with_data_source,
/// and should be kept in sync with it.
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn new_with_data_source<'a, D: BidiDataSource>(
data_source: &D,
text: &'a str,
default_para_level: Option<Level>,
) -> ParagraphBidiInfo<'a> {
// Here we could create a ParagraphInitialInfo struct to parallel the one
// used by BidiInfo, but there doesn't seem any compelling reason for it.
let (original_classes, paragraph_level, is_pure_ltr, has_isolate_controls) =
compute_initial_info(data_source, text, default_para_level, None);
let mut levels = Vec::<Level>::with_capacity(text.len());
let mut processing_classes = original_classes.clone();
let para_info = ParagraphInfo {
range: Range {
start: 0,
end: text.len(),
},
level: paragraph_level,
};
compute_bidi_info_for_para(
data_source,
¶_info,
is_pure_ltr,
has_isolate_controls,
text,
&original_classes,
&mut processing_classes,
&mut levels,
);
ParagraphBidiInfo {
text,
original_classes,
levels,
paragraph_level,
is_pure_ltr,
}
}
/// Produce the levels for this paragraph as needed for reordering, one level per *byte*
/// in the paragraph. The returned vector includes bytes that are not included
/// in the `line`, but will not adjust them.
///
/// See BidiInfo::reordered_levels for details.
///
/// (This should be kept in sync with BidiInfo::reordered_levels.)
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn reordered_levels(&self, line: Range<usize>) -> Vec<Level> {
assert!(line.start <= self.levels.len());
assert!(line.end <= self.levels.len());
let mut levels = self.levels.clone();
let line_classes = &self.original_classes[line.clone()];
let line_levels = &mut levels[line.clone()];
reorder_levels(
line_classes,
line_levels,
self.text.subrange(line),
self.paragraph_level,
);
levels
}
/// Produce the levels for this paragraph as needed for reordering, one level per *character*
/// in the paragraph. The returned vector includes characters that are not included
/// in the `line`, but will not adjust them.
///
/// See BidiInfo::reordered_levels_per_char for details.
///
/// (This should be kept in sync with BidiInfo::reordered_levels_per_char.)
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn reordered_levels_per_char(&self, line: Range<usize>) -> Vec<Level> {
let levels = self.reordered_levels(line);
self.text.char_indices().map(|(i, _)| levels[i]).collect()
}
/// Re-order a line based on resolved levels and return the line in display order.
///
/// See BidiInfo::reorder_line for details.
///
/// (This should be kept in sync with BidiInfo::reorder_line.)
#[cfg_attr(feature = "flame_it", flamer::flame)]
pub fn reorder_line(&self, line: Range<usize>) -> Cow<'text, str> {
if !level::has_rtl(&self.levels[line.clone()]) {
return self.text[line].into();
}
let (levels, runs) = self.visual_runs(line.clone());
reorder_line(self.text, line, levels, runs)
}
/// Reorders pre-calculated levels of a sequence of characters.
///
/// See BidiInfo::reorder_visual for details.
#[cfg_attr(feature = "flame_it", flamer::flame)]
#[inline]
pub fn reorder_visual(levels: &[Level]) -> Vec<usize> {
reorder_visual(levels)
}
/// Find the level runs within a line and return them in visual order.
///
/// `line` is a range of bytes indices within `levels`.
///
/// See BidiInfo::visual_runs for details.
///
/// (This should be kept in sync with BidiInfo::visual_runs.)
#[cfg_attr(feature = "flame_it", flamer::flame)]
#[inline]
pub fn visual_runs(&self, line: Range<usize>) -> (Vec<Level>, Vec<LevelRun>) {
let levels = self.reordered_levels(line.clone());
visual_runs_for_line(levels, &line)
}
/// 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
#[inline]
pub fn has_rtl(&self) -> bool {
!self.is_pure_ltr
}
/// Return the paragraph's Direction (Ltr, Rtl, or Mixed) based on its levels.
#[inline]
pub fn direction(&self) -> Direction {
para_direction(&self.levels)
}
}
/// Return a line of the text in display order based on resolved levels.
///
/// `text` the full text passed to the `BidiInfo` or `ParagraphBidiInfo` for analysis
/// `line` a range of byte indices within `text` corresponding to one line
/// `levels` array of `Level` values, with `line`'s levels reordered into visual order
/// `runs` array of `LevelRun`s in visual order
///
/// (`levels` and `runs` are the result of calling `BidiInfo::visual_runs()` or
/// `ParagraphBidiInfo::visual_runs()` for the line of interest.)
///
/// Returns: the reordered text of the line.
///
/// This does not apply [Rule L3] or [Rule L4] around combining characters or mirroring.
///
/// [Rule L3]: https://www.unicode.org/reports/tr9/#L3
/// [Rule L4]: https://www.unicode.org/reports/tr9/#L4
fn reorder_line(
text: &str,
line: Range<usize>,
levels: Vec<Level>,
runs: Vec<LevelRun>,
) -> Cow<'_, str> {
// If all isolating run sequences are LTR, no reordering is needed
if runs.iter().all(|run| levels[run.start].is_ltr()) {
return text[line].into();
}
let mut result = String::with_capacity(line.len());
for run in runs {
if levels[run.start].is_rtl() {
result.extend(text[run].chars().rev());
} else {
result.push_str(&text[run]);
}
}
result.into()
}
/// Find the level runs within a line and return them in visual order.
///
/// `line` is a range of code-unit indices within `levels`.
///
/// The first return value is a vector of levels used by the reordering algorithm,
/// i.e. the result of [Rule L1]. The second return value is a vector of level runs,
/// the result of [Rule L2], showing the visual order that each level run (a run of text with the
/// same level) should be displayed. Within each run, the display order can be checked
/// against the Level vector.
///
/// This does not handle [Rule L3] (combining characters) or [Rule L4] (mirroring),
/// as that should be handled by the engine using this API.
///
/// Conceptually, this is the same as running [`reordered_levels()`] followed by
/// [`reorder_visual()`], however it returns the result as a list of level runs instead
/// of producing a level map, since one may wish to deal with the fact that this is operating on
/// byte rather than character indices.
///
/// <http://www.unicode.org/reports/tr9/#Reordering_Resolved_Levels>
///
/// [Rule L1]: https://www.unicode.org/reports/tr9/#L1
/// [Rule L2]: https://www.unicode.org/reports/tr9/#L2
/// [Rule L3]: https://www.unicode.org/reports/tr9/#L3
/// [Rule L4]: https://www.unicode.org/reports/tr9/#L4
fn visual_runs_for_line(levels: Vec<Level>, line: &Range<usize>) -> (Vec<Level>, Vec<LevelRun>) {
// Find consecutive level runs.
let mut runs = Vec::new();
let mut start = line.start;
let mut run_level = levels[start];
let mut min_level = run_level;
let mut max_level = run_level;
for (i, &new_level) in levels.iter().enumerate().take(line.end).skip(start + 1) {
if new_level != run_level {
// End of the previous run, start of a new one.
runs.push(start..i);
start = i;
run_level = new_level;
min_level = cmp::min(run_level, min_level);
max_level = cmp::max(run_level, max_level);
}
}
runs.push(start..line.end);
let run_count = runs.len();
// Re-order the odd runs.
// <http://www.unicode.org/reports/tr9/#L2>
// Stop at the lowest *odd* level.
min_level = min_level.new_lowest_ge_rtl().expect("Level error");
// This loop goes through contiguous chunks of level runs that have a level
// ≥ max_level and reverses their contents, reducing max_level by 1 each time.
while max_level >= min_level {
// Look for the start of a sequence of consecutive runs of max_level or higher.
let mut seq_start = 0;
while seq_start < run_count {
if levels[runs[seq_start].start] < max_level {
seq_start += 1;
continue;
}
// Found the start of a sequence. Now find the end.
let mut seq_end = seq_start + 1;
while seq_end < run_count {
if levels[runs[seq_end].start] < max_level {
break;
}
seq_end += 1;
}
// Reverse the runs within this sequence.
runs[seq_start..seq_end].reverse();
seq_start = seq_end;
}
max_level
.lower(1)
.expect("Lowering embedding level below zero");
}
(levels, runs)
}
/// Reorders pre-calculated levels of a sequence of characters.
///
/// NOTE: This is a convenience method that does not use a `Paragraph` object. It is
/// intended to be used when an application has determined the levels of the objects (character sequences)
/// and just needs to have them reordered.
///
/// the index map will result in `indexMap[visualIndex]==logicalIndex`.
///
/// This only runs [Rule L2](http://www.unicode.org/reports/tr9/#L2) as it does not have
/// information about the actual text.
///
/// Furthermore, if `levels` is an array that is aligned with code units, bytes within a codepoint may be
/// reversed. You may need to fix up the map to deal with this. Alternatively, only pass in arrays where each `Level`
/// is for a single code point.
fn reorder_visual(levels: &[Level]) -> Vec<usize> {
// Gets the next range of characters after start_index with a level greater
// than or equal to `max`
fn next_range(levels: &[level::Level], mut start_index: usize, max: Level) -> Range<usize> {
if levels.is_empty() || start_index >= levels.len() {
return start_index..start_index;
}
while let Some(l) = levels.get(start_index) {
if *l >= max {
break;
}
start_index += 1;
}
if levels.get(start_index).is_none() {
// If at the end of the array, adding one will
// produce an out-of-range end element
return start_index..start_index;
}
let mut end_index = start_index + 1;
while let Some(l) = levels.get(end_index) {
if *l < max {
return start_index..end_index;
}
end_index += 1;
}
start_index..end_index
}
// This implementation is similar to the L2 implementation in `visual_runs()`
// but it cannot benefit from a precalculated LevelRun vector so needs to be different.
if levels.is_empty() {
return vec![];
}
// Get the min and max levels
let (mut min, mut max) = levels
.iter()
.fold((levels[0], levels[0]), |(min, max), &l| {
(cmp::min(min, l), cmp::max(max, l))
});
// Initialize an index map
let mut result: Vec<usize> = (0..levels.len()).collect();
if min == max && min.is_ltr() {
// Everything is LTR and at the same level, do nothing
return result;
}
// Stop at the lowest *odd* level, since everything below that
// is LTR and does not need further reordering
min = min.new_lowest_ge_rtl().expect("Level error");
// For each max level, take all contiguous chunks of
// levels ≥ max and reverse them
//
// We can do this check with the original levels instead of checking reorderings because all
// prior reorderings will have been for contiguous chunks of levels >> max, which will
// be a subset of these chunks anyway.
while min <= max {
let mut range = 0..0;
loop {
range = next_range(levels, range.end, max);
result[range.clone()].reverse();
if range.end >= levels.len() {
break;
}
}
max.lower(1).expect("Level error");
}
result
}
/// The core of BidiInfo initialization, factored out into a function that both
/// the utf-8 and utf-16 versions of BidiInfo can use.
fn compute_bidi_info_for_para<'a, D: BidiDataSource, T: TextSource<'a> + ?Sized>(
data_source: &D,
para: &ParagraphInfo,
is_pure_ltr: bool,
has_isolate_controls: bool,
text: &'a T,
original_classes: &[BidiClass],
processing_classes: &mut [BidiClass],
levels: &mut Vec<Level>,
) {
let new_len = levels.len() + para.range.len();
levels.resize(new_len, para.level);
if para.level == LTR_LEVEL && is_pure_ltr {
return;
}
let processing_classes = &mut processing_classes[para.range.clone()];
let levels = &mut levels[para.range.clone()];
let mut level_runs = LevelRunVec::new();
explicit::compute(
text,
para.level,
original_classes,
levels,
processing_classes,
&mut level_runs,
);
let mut sequences = prepare::IsolatingRunSequenceVec::new();
prepare::isolating_run_sequences(
para.level,
original_classes,
levels,
level_runs,
has_isolate_controls,
&mut sequences,
);
for sequence in &sequences {
implicit::resolve_weak(text, sequence, processing_classes);
implicit::resolve_neutral(
text,
data_source,
sequence,
levels,
original_classes,
processing_classes,
);
}
implicit::resolve_levels(processing_classes, levels);
assign_levels_to_removed_chars(para.level, original_classes, levels);
}
/// Produce the levels for this paragraph as needed for reordering, one level per *code unit*
/// in the paragraph. The returned vector includes code units that are not included
/// in the `line`, but will not adjust them.
///
/// This runs [Rule L1]
///
/// [Rule L1]: https://www.unicode.org/reports/tr9/#L1
fn reorder_levels<'a, T: TextSource<'a> + ?Sized>(
line_classes: &[BidiClass],
line_levels: &mut [Level],
line_text: &'a T,
para_level: Level,
) {
// Reset some whitespace chars to paragraph level.
// <http://www.unicode.org/reports/tr9/#L1>
let mut reset_from: Option<usize> = Some(0);
let mut reset_to: Option<usize> = None;
let mut prev_level = para_level;
for (i, c) in line_text.char_indices() {
match line_classes[i] {
// Segment separator, Paragraph separator
B | S => {
assert_eq!(reset_to, None);
reset_to = Some(i + T::char_len(c));
if reset_from.is_none() {
reset_from = Some(i);
}
}
// Whitespace, isolate formatting
WS | FSI | LRI | RLI | PDI => {
if reset_from.is_none() {
reset_from = Some(i);
}
}
// <https://www.unicode.org/reports/tr9/#Retaining_Explicit_Formatting_Characters>
// same as above + set the level
RLE | LRE | RLO | LRO | PDF | BN => {
if reset_from.is_none() {
reset_from = Some(i);
}
// also set the level to previous
line_levels[i] = prev_level;
}
_ => {
reset_from = None;
}
}
if let (Some(from), Some(to)) = (reset_from, reset_to) {
for level in &mut line_levels[from..to] {
*level = para_level;
}
reset_from = None;
reset_to = None;
}
prev_level = line_levels[i];
}
if let Some(from) = reset_from {
for level in &mut line_levels[from..] {
*level = para_level;
}
}
}
/// Contains a reference of `BidiInfo` and one of its `paragraphs`.
/// And it supports all operation in the `Paragraph` that needs also its
/// `BidiInfo` such as `direction`.
#[derive(Debug)]
pub struct Paragraph<'a, 'text> {
pub info: &'a BidiInfo<'text>,
pub para: &'a ParagraphInfo,
}
impl<'a, 'text> Paragraph<'a, 'text> {
#[inline]
pub fn new(info: &'a BidiInfo<'text>, para: &'a ParagraphInfo) -> Paragraph<'a, 'text> {
Paragraph { info, para }
}
/// Returns if the paragraph is Left direction, right direction or mixed.
#[inline]
pub fn direction(&self) -> Direction {
para_direction(&self.info.levels[self.para.range.clone()])
}
/// Returns the `Level` of a certain character in the paragraph.
#[inline]
pub fn level_at(&self, pos: usize) -> Level {
let actual_position = self.para.range.start + pos;
self.info.levels[actual_position]
}
}
/// Return the directionality of the paragraph (Left, Right or Mixed) from its levels.
#[cfg_attr(feature = "flame_it", flamer::flame)]
fn para_direction(levels: &[Level]) -> Direction {
let mut ltr = false;
let mut rtl = false;
for level in levels {
if level.is_ltr() {
ltr = true;
if rtl {
return Direction::Mixed;
}
}
if level.is_rtl() {
rtl = true;
if ltr {
return Direction::Mixed;
}
}
}
if ltr {
return Direction::Ltr;
}
Direction::Rtl
}
/// Assign levels to characters removed by rule X9.
///
/// The levels assigned to these characters are not specified by the algorithm. This function
/// assigns each one the level of the previous character, to avoid breaking level runs.
#[cfg_attr(feature = "flame_it", flamer::flame)]
fn assign_levels_to_removed_chars(para_level: Level, classes: &[BidiClass], levels: &mut [Level]) {
for i in 0..levels.len() {
if prepare::removed_by_x9(classes[i]) {
levels[i] = if i > 0 { levels[i - 1] } else { para_level };
}
}
}
/// Get the base direction of the text provided according to the Unicode Bidirectional Algorithm.
///
/// See rules P2 and P3.
///
/// The base direction is derived from the first character in the string with bidi character type
/// L, R, or AL. If the first such character has type L, Direction::Ltr is returned. If the first
/// such character has type R or AL, Direction::Rtl is returned.
///
/// If the string does not contain any character of these types (outside of embedded isolate runs),
/// then Direction::Mixed is returned (but should be considered as meaning "neutral" or "unknown",
/// not in fact mixed directions).
///
/// This is a lightweight function for use when only the base direction is needed and no further
/// bidi processing of the text is needed.
///
/// If the text contains paragraph separators, this function considers only the first paragraph.
#[cfg(feature = "hardcoded-data")]
#[inline]
pub fn get_base_direction<'a, T: TextSource<'a> + ?Sized>(text: &'a T) -> Direction {
get_base_direction_with_data_source(&HardcodedBidiData, text)
}
/// Get the base direction of the text provided according to the Unicode Bidirectional Algorithm,
/// considering the full text if the first paragraph is all-neutral.
///
/// This is the same as get_base_direction except that it does not stop at the first block
/// separator, but just resets the embedding level and continues to look for a strongly-
/// directional character. So the result will be the base direction of the first paragraph
/// that is not purely neutral characters.
#[cfg(feature = "hardcoded-data")]
#[inline]
pub fn get_base_direction_full<'a, T: TextSource<'a> + ?Sized>(text: &'a T) -> Direction {
get_base_direction_full_with_data_source(&HardcodedBidiData, text)
}
#[inline]
pub fn get_base_direction_with_data_source<'a, D: BidiDataSource, T: TextSource<'a> + ?Sized>(
data_source: &D,
text: &'a T,
) -> Direction {
get_base_direction_impl(data_source, text, false)
}
#[inline]
pub fn get_base_direction_full_with_data_source<
'a,
D: BidiDataSource,
T: TextSource<'a> + ?Sized,
>(
data_source: &D,
text: &'a T,
) -> Direction {
get_base_direction_impl(data_source, text, true)
}
fn get_base_direction_impl<'a, D: BidiDataSource, T: TextSource<'a> + ?Sized>(
data_source: &D,
text: &'a T,
use_full_text: bool,
) -> Direction {
let mut isolate_level = 0;
for c in text.chars() {
match data_source.bidi_class(c) {
LRI | RLI | FSI => isolate_level += 1,
PDI if isolate_level > 0 => isolate_level -= 1,
L if isolate_level == 0 => return Direction::Ltr,
R | AL if isolate_level == 0 => return Direction::Rtl,
B if !use_full_text => break,
B if use_full_text => isolate_level = 0,
_ => (),
}
}
// If no strong char was found, return Mixed. Normally this will be treated as Ltr by callers
// (see rule P3), but we don't map this to Ltr here so that a caller that wants to apply other
// heuristics to an all-neutral paragraph can tell the difference.
Direction::Mixed
}
/// Implementation of TextSource for UTF-8 text (a string slice).
impl<'text> TextSource<'text> for str {
type CharIter = core::str::Chars<'text>;
type CharIndexIter = core::str::CharIndices<'text>;
type IndexLenIter = Utf8IndexLenIter<'text>;
#[inline]
fn len(&self) -> usize {
(self as &str).len()
}
#[inline]
fn char_at(&self, index: usize) -> Option<(char, usize)> {
if let Some(slice) = self.get(index..) {
if let Some(ch) = slice.chars().next() {
return Some((ch, ch.len_utf8()));
}
}
None
}
#[inline]
fn subrange(&self, range: Range<usize>) -> &Self {
&(self as &str)[range]
}
#[inline]
fn chars(&'text self) -> Self::CharIter {
(self as &str).chars()
}
#[inline]
fn char_indices(&'text self) -> Self::CharIndexIter {
(self as &str).char_indices()
}
#[inline]
fn indices_lengths(&'text self) -> Self::IndexLenIter {
Utf8IndexLenIter::new(self)
}
#[inline]
fn char_len(ch: char) -> usize {
ch.len_utf8()
}
}
/// Iterator over (UTF-8) string slices returning (index, char_len) tuple.
#[derive(Debug)]
pub struct Utf8IndexLenIter<'text> {
iter: CharIndices<'text>,
}
impl<'text> Utf8IndexLenIter<'text> {
#[inline]
pub fn new(text: &'text str) -> Self {
Utf8IndexLenIter {
iter: text.char_indices(),
}
}
}
impl Iterator for Utf8IndexLenIter<'_> {
type Item = (usize, usize);
#[inline]
fn next(&mut self) -> Option<Self::Item> {
if let Some((pos, ch)) = self.iter.next() {
return Some((pos, ch.len_utf8()));
}
None
}
}
#[cfg(test)]
fn to_utf16(s: &str) -> Vec<u16> {
s.encode_utf16().collect()
}
#[cfg(test)]
#[cfg(feature = "hardcoded-data")]
mod tests {
use super::*;
use utf16::{
BidiInfo as BidiInfoU16, InitialInfo as InitialInfoU16, Paragraph as ParagraphU16,
ParagraphBidiInfo as ParagraphBidiInfoU16,
};
#[test]
fn test_utf16_text_source() {
let text: &[u16] =
&[0x41, 0xD801, 0xDC01, 0x20, 0xD800, 0x20, 0xDFFF, 0x20, 0xDC00, 0xD800];
assert_eq!(text.char_at(0), Some(('A', 1)));
assert_eq!(text.char_at(1), Some(('\u{10401}', 2)));
assert_eq!(text.char_at(2), None);
assert_eq!(text.char_at(3), Some((' ', 1)));
assert_eq!(text.char_at(4), Some((char::REPLACEMENT_CHARACTER, 1)));
assert_eq!(text.char_at(5), Some((' ', 1)));
assert_eq!(text.char_at(6), Some((char::REPLACEMENT_CHARACTER, 1)));
assert_eq!(text.char_at(7), Some((' ', 1)));
assert_eq!(text.char_at(8), Some((char::REPLACEMENT_CHARACTER, 1)));
assert_eq!(text.char_at(9), Some((char::REPLACEMENT_CHARACTER, 1)));
assert_eq!(text.char_at(10), None);
}
#[test]
fn test_utf16_char_iter() {
let text: &[u16] =
&[0x41, 0xD801, 0xDC01, 0x20, 0xD800, 0x20, 0xDFFF, 0x20, 0xDC00, 0xD800];
assert_eq!(text.len(), 10);
assert_eq!(text.chars().count(), 9);
let mut chars = text.chars();
assert_eq!(chars.next(), Some('A'));
assert_eq!(chars.next(), Some('\u{10401}'));
assert_eq!(chars.next(), Some(' '));
assert_eq!(chars.next(), Some('\u{FFFD}'));
assert_eq!(chars.next(), Some(' '));
assert_eq!(chars.next(), Some('\u{FFFD}'));
assert_eq!(chars.next(), Some(' '));
assert_eq!(chars.next(), Some('\u{FFFD}'));
assert_eq!(chars.next(), Some('\u{FFFD}'));
assert_eq!(chars.next(), None);
}
#[test]
fn test_initial_text_info() {
let tests = vec![
(
// text
"a1",
// expected bidi classes per utf-8 byte
vec![L, EN],
// expected paragraph-info for utf-8
vec![ParagraphInfo {
range: 0..2,
level: LTR_LEVEL,
}],
// expected bidi classes per utf-16 code unit
vec![L, EN],
// expected paragraph-info for utf-16
vec![ParagraphInfo {
range: 0..2,
level: LTR_LEVEL,
}],
),
(
// Arabic, space, Hebrew
"\u{0639} \u{05D0}",
vec![AL, AL, WS, R, R],
vec![ParagraphInfo {
range: 0..5,
level: RTL_LEVEL,
}],
vec![AL, WS, R],
vec![ParagraphInfo {
range: 0..3,
level: RTL_LEVEL,
}],
),
(
// SMP characters from Kharoshthi, Cuneiform, Adlam:
"\u{10A00}\u{12000}\u{1E900}",
vec![R, R, R, R, L, L, L, L, R, R, R, R],
vec![ParagraphInfo {
range: 0..12,
level: RTL_LEVEL,
}],
vec![R, R, L, L, R, R],
vec![ParagraphInfo {
range: 0..6,
level: RTL_LEVEL,
}],
),
(
"a\u{2029}b",
vec![L, B, B, B, L],
vec![
ParagraphInfo {
range: 0..4,
level: LTR_LEVEL,
},
ParagraphInfo {
range: 4..5,
level: LTR_LEVEL,
},
],
vec![L, B, L],
vec![
ParagraphInfo {
range: 0..2,
level: LTR_LEVEL,
},
ParagraphInfo {
range: 2..3,
level: LTR_LEVEL,
},
],
),
(
"\u{2068}א\u{2069}a", // U+2068 FSI, U+2069 PDI
vec![RLI, RLI, RLI, R, R, PDI, PDI, PDI, L],
vec![ParagraphInfo {
range: 0..9,
level: LTR_LEVEL,
}],
vec![RLI, R, PDI, L],
vec![ParagraphInfo {
range: 0..4,
level: LTR_LEVEL,
}],
),
];
for t in tests {
assert_eq!(
InitialInfo::new(t.0, None),
InitialInfo {
text: t.0,
original_classes: t.1,
paragraphs: t.2,
}
);
let text = &to_utf16(t.0);
assert_eq!(
InitialInfoU16::new(text, None),
InitialInfoU16 {
text,
original_classes: t.3,
paragraphs: t.4,
}
);
}
}
#[test]
#[cfg(feature = "hardcoded-data")]
fn test_process_text() {
let tests = vec![
(
// text
"",
// base level
Some(RTL_LEVEL),
// levels
Level::vec(&[]),
// original_classes
vec![],
// paragraphs
vec![],
// levels_u16
Level::vec(&[]),
// original_classes_u16
vec![],
// paragraphs_u16
vec![],
),
(
// text
"abc123",
// base level
Some(LTR_LEVEL),
// levels
Level::vec(&[0, 0, 0, 0, 0, 0]),
// original_classes
vec![L, L, L, EN, EN, EN],
// paragraphs
vec![ParagraphInfo {
range: 0..6,
level: LTR_LEVEL,
}],
// levels_u16
Level::vec(&[0, 0, 0, 0, 0, 0]),
// original_classes_u16
vec![L, L, L, EN, EN, EN],
// paragraphs_u16
vec![ParagraphInfo {
range: 0..6,
level: LTR_LEVEL,
}],
),
(
"abc \u{05D0}\u{05D1}\u{05D2}",
Some(LTR_LEVEL),
Level::vec(&[0, 0, 0, 0, 1, 1, 1, 1, 1, 1]),
vec![L, L, L, WS, R, R, R, R, R, R],
vec![ParagraphInfo {
range: 0..10,
level: LTR_LEVEL,
}],
Level::vec(&[0, 0, 0, 0, 1, 1, 1]),
vec![L, L, L, WS, R, R, R],
vec![ParagraphInfo {
range: 0..7,
level: LTR_LEVEL,
}],
),
(
"abc \u{05D0}\u{05D1}\u{05D2}",
Some(RTL_LEVEL),
Level::vec(&[2, 2, 2, 1, 1, 1, 1, 1, 1, 1]),
vec![L, L, L, WS, R, R, R, R, R, R],
vec![ParagraphInfo {
range: 0..10,
level: RTL_LEVEL,
}],
Level::vec(&[2, 2, 2, 1, 1, 1, 1]),
vec![L, L, L, WS, R, R, R],
vec![ParagraphInfo {
range: 0..7,
level: RTL_LEVEL,
}],
),
(
"\u{05D0}\u{05D1}\u{05D2} abc",
Some(LTR_LEVEL),
Level::vec(&[1, 1, 1, 1, 1, 1, 0, 0, 0, 0]),
vec![R, R, R, R, R, R, WS, L, L, L],
vec![ParagraphInfo {
range: 0..10,
level: LTR_LEVEL,
}],
Level::vec(&[1, 1, 1, 0, 0, 0, 0]),
vec![R, R, R, WS, L, L, L],
vec![ParagraphInfo {
range: 0..7,
level: LTR_LEVEL,
}],
),
(
"\u{05D0}\u{05D1}\u{05D2} abc",
None,
Level::vec(&[1, 1, 1, 1, 1, 1, 1, 2, 2, 2]),
vec![R, R, R, R, R, R, WS, L, L, L],
vec![ParagraphInfo {
range: 0..10,
level: RTL_LEVEL,
}],
Level::vec(&[1, 1, 1, 1, 2, 2, 2]),
vec![R, R, R, WS, L, L, L],
vec![ParagraphInfo {
range: 0..7,
level: RTL_LEVEL,
}],
),
(
"\u{063A}2\u{0638} \u{05D0}2\u{05D2}",
Some(LTR_LEVEL),
Level::vec(&[1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1]),
vec![AL, AL, EN, AL, AL, WS, R, R, EN, R, R],
vec![ParagraphInfo {
range: 0..11,
level: LTR_LEVEL,
}],
Level::vec(&[1, 2, 1, 1, 1, 2, 1]),
vec![AL, EN, AL, WS, R, EN, R],
vec![ParagraphInfo {
range: 0..7,
level: LTR_LEVEL,
}],
),
(
"a א.\nג",
None,
Level::vec(&[0, 0, 1, 1, 0, 0, 1, 1]),
vec![L, WS, R, R, CS, B, R, R],
vec![
ParagraphInfo {
range: 0..6,
level: LTR_LEVEL,
},
ParagraphInfo {
range: 6..8,
level: RTL_LEVEL,
},
],
Level::vec(&[0, 0, 1, 0, 0, 1]),
vec![L, WS, R, CS, B, R],
vec![
ParagraphInfo {
range: 0..5,
level: LTR_LEVEL,
},
ParagraphInfo {
range: 5..6,
level: RTL_LEVEL,
},
],
),
// BidiTest:69635 (AL ET EN)
(
"\u{060B}\u{20CF}\u{06F9}",
None,
Level::vec(&[1, 1, 1, 1, 1, 2, 2]),
vec![AL, AL, ET, ET, ET, EN, EN],
vec![ParagraphInfo {
range: 0..7,
level: RTL_LEVEL,
}],
Level::vec(&[1, 1, 2]),
vec![AL, ET, EN],
vec![ParagraphInfo {
range: 0..3,
level: RTL_LEVEL,
}],
),
];
for t in tests {
assert_eq!(
BidiInfo::new(t.0, t.1),
BidiInfo {
text: t.0,
levels: t.2.clone(),
original_classes: t.3.clone(),
paragraphs: t.4.clone(),
}
);
// If it was empty, also test that ParagraphBidiInfo handles it safely.
if t.4.len() == 0 {
assert_eq!(
ParagraphBidiInfo::new(t.0, t.1),
ParagraphBidiInfo {
text: t.0,
original_classes: t.3.clone(),
levels: t.2.clone(),
paragraph_level: RTL_LEVEL,
is_pure_ltr: true,
}
)
}
// If it was a single paragraph, also test ParagraphBidiInfo.
if t.4.len() == 1 {
assert_eq!(
ParagraphBidiInfo::new(t.0, t.1),
ParagraphBidiInfo {
text: t.0,
original_classes: t.3,
levels: t.2.clone(),
paragraph_level: t.4[0].level,
is_pure_ltr: !level::has_rtl(&t.2),
}
)
}
let text = &to_utf16(t.0);
assert_eq!(
BidiInfoU16::new(text, t.1),
BidiInfoU16 {
text,
levels: t.5.clone(),
original_classes: t.6.clone(),
paragraphs: t.7.clone(),
}
);
if t.7.len() == 1 {
assert_eq!(
ParagraphBidiInfoU16::new(text, t.1),
ParagraphBidiInfoU16 {
text: text,
original_classes: t.6.clone(),
levels: t.5.clone(),
paragraph_level: t.7[0].level,
is_pure_ltr: !level::has_rtl(&t.5),
}
)
}
}
}
#[test]
#[cfg(feature = "hardcoded-data")]
fn test_paragraph_bidi_info() {
// Passing text that includes a paragraph break to the ParagraphBidiInfo API:
// this is a misuse of the API by the client, but our behavior is safe &
// consistent. The embedded paragraph break acts like a separator (tab) would.
let tests = vec![
(
"a א.\nג",
None,
// utf-8 results:
vec![L, WS, R, R, CS, B, R, R],
Level::vec(&[0, 0, 1, 1, 1, 1, 1, 1]),
// utf-16 results:
vec![L, WS, R, CS, B, R],
Level::vec(&[0, 0, 1, 1, 1, 1]),
--> --------------------
--> maximum size reached
--> --------------------
[ Dauer der Verarbeitung: 0.46 Sekunden
(vorverarbeitet)
]
|
2026-04-02
|
