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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /third_party/rust/unicode-bidi/src/lib.rs | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/unicode-bidi/src/lib.rs')
-rw-r--r-- | third_party/rust/unicode-bidi/src/lib.rs | 2242 |
1 files changed, 2242 insertions, 0 deletions
diff --git a/third_party/rust/unicode-bidi/src/lib.rs b/third_party/rust/unicode-bidi/src/lib.rs new file mode 100644 index 0000000000..1072b67fe0 --- /dev/null +++ b/third_party/rust/unicode-bidi/src/lib.rs @@ -0,0 +1,2242 @@ +// 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 convenient 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; + +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; + +#[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; + +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). + pure_ltr: Vec<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 pure_ltr = Vec::<bool>::new(); + let (original_classes, _, _) = compute_initial_info( + data_source, + text, + default_para_level, + Some((&mut paragraphs, &mut pure_ltr)), + ); + + InitialInfoExt { + base: InitialInfo { + text, + original_classes, + paragraphs, + }, + pure_ltr, + } + } +} + +/// 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<bool>)>, +) -> (Vec<BidiClass>, Level, 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. + let mut isolate_stack = Vec::new(); + + debug_assert!( + if let Some((ref paragraphs, ref pure_ltr)) = split_paragraphs { + paragraphs.is_empty() && pure_ltr.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; + + #[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 pure_ltr)) = 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), + }); + pure_ltr.push(is_pure_ltr); + // 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; + 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; + isolate_stack.push(i); + } + + PDI => { + isolate_stack.pop(); + } + + _ => {} + } + } + + if let Some((paragraphs, pure_ltr)) = split_paragraphs { + if para_start < text.len() { + paragraphs.push(ParagraphInfo { + range: para_start..text.len(), + level: para_level.unwrap_or(LTR_LEVEL), + }); + pure_ltr.push(is_pure_ltr); + } + debug_assert_eq!(paragraphs.len(), pure_ltr.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, + ) +} + +/// 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, pure_ltr, .. } = + 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, is_pure_ltr) in base.paragraphs.iter().zip(pure_ltr.iter()) { + let text = &text[para.range.clone()]; + let original_classes = &base.original_classes[para.range.clone()]; + + compute_bidi_info_for_para( + data_source, + para, + *is_pure_ltr, + 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) = + 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, + 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>( + text: &'text str, + line: Range<usize>, + levels: Vec<Level>, + runs: Vec<LevelRun>, +) -> Cow<'text, 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, + 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()]; + + explicit::compute( + text, + para.level, + original_classes, + levels, + processing_classes, + ); + + let sequences = prepare::isolating_run_sequences(para.level, original_classes, levels); + 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 == None { + reset_from = Some(i); + } + } + // Whitespace, isolate formatting + WS | FSI | LRI | RLI | PDI => { + if reset_from == 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 == 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 = isolate_level + 1, + PDI if isolate_level > 0 => isolate_level = 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 + "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 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]), + // paragraph level; is_pure_ltr + LTR_LEVEL, + false, + ), + ( + "\u{5d1} a.\nb.", + None, + // utf-8 results: + vec![R, R, WS, L, CS, B, L, CS], + Level::vec(&[1, 1, 1, 2, 2, 2, 2, 1]), + // utf-16 results: + vec![R, WS, L, CS, B, L, CS], + Level::vec(&[1, 1, 2, 2, 2, 2, 1]), + // paragraph level; is_pure_ltr + RTL_LEVEL, + false, + ), + ( + "a א.\tג", + None, + // utf-8 results: + vec![L, WS, R, R, CS, S, R, R], + Level::vec(&[0, 0, 1, 1, 1, 1, 1, 1]), + // utf-16 results: + vec![L, WS, R, CS, S, R], + Level::vec(&[0, 0, 1, 1, 1, 1]), + // paragraph level; is_pure_ltr + LTR_LEVEL, + false, + ), + ( + "\u{5d1} a.\tb.", + None, + // utf-8 results: + vec![R, R, WS, L, CS, S, L, CS], + Level::vec(&[1, 1, 1, 2, 2, 2, 2, 1]), + // utf-16 results: + vec![R, WS, L, CS, S, L, CS], + Level::vec(&[1, 1, 2, 2, 2, 2, 1]), + // paragraph level; is_pure_ltr + RTL_LEVEL, + false, + ), + ]; + + for t in tests { + assert_eq!( + ParagraphBidiInfo::new(t.0, t.1), + ParagraphBidiInfo { + text: t.0, + original_classes: t.2, + levels: t.3, + paragraph_level: t.6, + is_pure_ltr: t.7, + } + ); + let text = &to_utf16(t.0); + assert_eq!( + ParagraphBidiInfoU16::new(text, t.1), + ParagraphBidiInfoU16 { + text: text, + original_classes: t.4, + levels: t.5, + paragraph_level: t.6, + is_pure_ltr: t.7, + } + ); + } + } + + #[test] + #[cfg(feature = "hardcoded-data")] + fn test_bidi_info_has_rtl() { + let tests = vec![ + // ASCII only + ("123", None, false), + ("123", Some(LTR_LEVEL), false), + ("123", Some(RTL_LEVEL), false), + ("abc", None, false), + ("abc", Some(LTR_LEVEL), false), + ("abc", Some(RTL_LEVEL), false), + ("abc 123", None, false), + ("abc\n123", None, false), + // With Hebrew + ("\u{05D0}\u{05D1}\u{05BC}\u{05D2}", None, true), + ("\u{05D0}\u{05D1}\u{05BC}\u{05D2}", Some(LTR_LEVEL), true), + ("\u{05D0}\u{05D1}\u{05BC}\u{05D2}", Some(RTL_LEVEL), true), + ("abc \u{05D0}\u{05D1}\u{05BC}\u{05D2}", None, true), + ("abc\n\u{05D0}\u{05D1}\u{05BC}\u{05D2}", None, true), + ("\u{05D0}\u{05D1}\u{05BC}\u{05D2} abc", None, true), + ("\u{05D0}\u{05D1}\u{05BC}\u{05D2}\nabc", None, true), + ("\u{05D0}\u{05D1}\u{05BC}\u{05D2} 123", None, true), + ("\u{05D0}\u{05D1}\u{05BC}\u{05D2}\n123", None, true), + ]; + + for t in tests { + assert_eq!(BidiInfo::new(t.0, t.1).has_rtl(), t.2); + assert_eq!(BidiInfoU16::new(&to_utf16(t.0), t.1).has_rtl(), t.2); + } + } + + #[cfg(feature = "hardcoded-data")] + fn reorder_paras(text: &str) -> Vec<Cow<'_, str>> { + let bidi_info = BidiInfo::new(text, None); + bidi_info + .paragraphs + .iter() + .map(|para| bidi_info.reorder_line(para, para.range.clone())) + .collect() + } + + #[cfg(feature = "hardcoded-data")] + fn reorder_paras_u16(text: &[u16]) -> Vec<Cow<'_, [u16]>> { + let bidi_info = BidiInfoU16::new(text, None); + bidi_info + .paragraphs + .iter() + .map(|para| bidi_info.reorder_line(para, para.range.clone())) + .collect() + } + + #[test] + #[cfg(feature = "hardcoded-data")] + fn test_reorder_line() { + let tests = vec![ + // Bidi_Class: L L L B L L L B L L L + ("abc\ndef\nghi", vec!["abc\n", "def\n", "ghi"]), + // Bidi_Class: L L EN B L L EN B L L EN + ("ab1\nde2\ngh3", vec!["ab1\n", "de2\n", "gh3"]), + // Bidi_Class: L L L B AL AL AL + ("abc\nابج", vec!["abc\n", "جبا"]), + // Bidi_Class: AL AL AL B L L L + ( + "\u{0627}\u{0628}\u{062C}\nabc", + vec!["\n\u{062C}\u{0628}\u{0627}", "abc"], + ), + ("1.-2", vec!["1.-2"]), + ("1-.2", vec!["1-.2"]), + ("abc אבג", vec!["abc גבא"]), + // Numbers being weak LTR characters, cannot reorder strong RTL + ("123 \u{05D0}\u{05D1}\u{05D2}", vec!["גבא 123"]), + ("abc\u{202A}def", vec!["abc\u{202A}def"]), + ( + "abc\u{202A}def\u{202C}ghi", + vec!["abc\u{202A}def\u{202C}ghi"], + ), + ( + "abc\u{2066}def\u{2069}ghi", + vec!["abc\u{2066}def\u{2069}ghi"], + ), + // Testing for RLE Character + ("\u{202B}abc אבג\u{202C}", vec!["\u{202b}גבא abc\u{202c}"]), + // Testing neutral characters + ("\u{05D0}בג? אבג", vec!["גבא ?גבא"]), + // Testing neutral characters with special case + ("A אבג?", vec!["A גבא?"]), + // Testing neutral characters with Implicit RTL Marker + ("A אבג?\u{200F}", vec!["A \u{200F}?גבא"]), + ("\u{05D0}בג abc", vec!["abc גבא"]), + ("abc\u{2067}.-\u{2069}ghi", vec!["abc\u{2067}-.\u{2069}ghi"]), + ( + "Hello, \u{2068}\u{202E}world\u{202C}\u{2069}!", + vec!["Hello, \u{2068}\u{202E}\u{202C}dlrow\u{2069}!"], + ), + // With mirrorable characters in RTL run + ("\u{05D0}(ב)ג.", vec![".ג)ב(א"]), + // With mirrorable characters on level boundary + ("\u{05D0}ב(גד[&ef].)gh", vec!["gh).]ef&[דג(בא"]), + ]; + + for t in tests { + assert_eq!(reorder_paras(t.0), t.1); + let expect_utf16 = t.1.iter().map(|v| to_utf16(v)).collect::<Vec<_>>(); + assert_eq!(reorder_paras_u16(&to_utf16(t.0)), expect_utf16); + } + } + + fn reordered_levels_for_paras(text: &str) -> Vec<Vec<Level>> { + let bidi_info = BidiInfo::new(text, None); + bidi_info + .paragraphs + .iter() + .map(|para| bidi_info.reordered_levels(para, para.range.clone())) + .collect() + } + + fn reordered_levels_per_char_for_paras(text: &str) -> Vec<Vec<Level>> { + let bidi_info = BidiInfo::new(text, None); + bidi_info + .paragraphs + .iter() + .map(|para| bidi_info.reordered_levels_per_char(para, para.range.clone())) + .collect() + } + + fn reordered_levels_for_paras_u16(text: &[u16]) -> Vec<Vec<Level>> { + let bidi_info = BidiInfoU16::new(text, None); + bidi_info + .paragraphs + .iter() + .map(|para| bidi_info.reordered_levels(para, para.range.clone())) + .collect() + } + + fn reordered_levels_per_char_for_paras_u16(text: &[u16]) -> Vec<Vec<Level>> { + let bidi_info = BidiInfoU16::new(text, None); + bidi_info + .paragraphs + .iter() + .map(|para| bidi_info.reordered_levels_per_char(para, para.range.clone())) + .collect() + } + + #[test] + #[cfg(feature = "hardcoded-data")] + fn test_reordered_levels() { + let tests = vec![ + // BidiTest:946 (LRI PDI) + ( + "\u{2067}\u{2069}", + vec![Level::vec(&[0, 0, 0, 0, 0, 0])], + vec![Level::vec(&[0, 0])], + vec![Level::vec(&[0, 0])], + ), + // BidiTest:69635 (AL ET EN) + ( + "\u{060B}\u{20CF}\u{06F9}", + vec![Level::vec(&[1, 1, 1, 1, 1, 2, 2])], + vec![Level::vec(&[1, 1, 2])], + vec![Level::vec(&[1, 1, 2])], + ), + ]; + + for t in tests { + assert_eq!(reordered_levels_for_paras(t.0), t.1); + assert_eq!(reordered_levels_per_char_for_paras(t.0), t.2); + let text = &to_utf16(t.0); + assert_eq!(reordered_levels_for_paras_u16(text), t.3); + assert_eq!(reordered_levels_per_char_for_paras_u16(text), t.2); + } + + let tests = vec![ + // BidiTest:291284 (AN RLI PDF R) + ( + "\u{0605}\u{2067}\u{202C}\u{0590}", + vec![&["2", "2", "0", "0", "0", "x", "x", "x", "1", "1"]], + vec![&["2", "0", "x", "1"]], + vec![&["2", "0", "x", "1"]], + ), + ]; + + for t in tests { + assert_eq!(reordered_levels_for_paras(t.0), t.1); + assert_eq!(reordered_levels_per_char_for_paras(t.0), t.2); + let text = &to_utf16(t.0); + assert_eq!(reordered_levels_for_paras_u16(text), t.3); + assert_eq!(reordered_levels_per_char_for_paras_u16(text), t.2); + } + + let text = "aa טֶ"; + let bidi_info = BidiInfo::new(text, None); + assert_eq!( + bidi_info.reordered_levels(&bidi_info.paragraphs[0], 3..7), + Level::vec(&[0, 0, 0, 1, 1, 1, 1]), + ); + + let text = &to_utf16(text); + let bidi_info = BidiInfoU16::new(text, None); + assert_eq!( + bidi_info.reordered_levels(&bidi_info.paragraphs[0], 1..4), + Level::vec(&[0, 0, 0, 1, 1]), + ); + } + + #[test] + fn test_paragraph_info_len() { + let text = "hello world"; + let bidi_info = BidiInfo::new(text, None); + assert_eq!(bidi_info.paragraphs.len(), 1); + assert_eq!(bidi_info.paragraphs[0].len(), text.len()); + + let text2 = "How are you"; + let whole_text = format!("{}\n{}", text, text2); + let bidi_info = BidiInfo::new(&whole_text, None); + assert_eq!(bidi_info.paragraphs.len(), 2); + + // The first paragraph include the paragraph separator. + // TODO: investigate if the paragraph separator character + // should not be part of any paragraph. + assert_eq!(bidi_info.paragraphs[0].len(), text.len() + 1); + assert_eq!(bidi_info.paragraphs[1].len(), text2.len()); + + let text = &to_utf16(text); + let bidi_info = BidiInfoU16::new(text, None); + assert_eq!(bidi_info.paragraphs.len(), 1); + assert_eq!(bidi_info.paragraphs[0].len(), text.len()); + + let text2 = &to_utf16(text2); + let whole_text = &to_utf16(&whole_text); + let bidi_info = BidiInfoU16::new(&whole_text, None); + assert_eq!(bidi_info.paragraphs.len(), 2); + + assert_eq!(bidi_info.paragraphs[0].len(), text.len() + 1); + assert_eq!(bidi_info.paragraphs[1].len(), text2.len()); + } + + #[test] + fn test_direction() { + let ltr_text = "hello world"; + let rtl_text = "أهلا بكم"; + let all_paragraphs = format!("{}\n{}\n{}{}", ltr_text, rtl_text, ltr_text, rtl_text); + let bidi_info = BidiInfo::new(&all_paragraphs, None); + assert_eq!(bidi_info.paragraphs.len(), 3); + let p_ltr = Paragraph::new(&bidi_info, &bidi_info.paragraphs[0]); + let p_rtl = Paragraph::new(&bidi_info, &bidi_info.paragraphs[1]); + let p_mixed = Paragraph::new(&bidi_info, &bidi_info.paragraphs[2]); + assert_eq!(p_ltr.direction(), Direction::Ltr); + assert_eq!(p_rtl.direction(), Direction::Rtl); + assert_eq!(p_mixed.direction(), Direction::Mixed); + + let all_paragraphs = &to_utf16(&all_paragraphs); + let bidi_info = BidiInfoU16::new(&all_paragraphs, None); + assert_eq!(bidi_info.paragraphs.len(), 3); + let p_ltr = ParagraphU16::new(&bidi_info, &bidi_info.paragraphs[0]); + let p_rtl = ParagraphU16::new(&bidi_info, &bidi_info.paragraphs[1]); + let p_mixed = ParagraphU16::new(&bidi_info, &bidi_info.paragraphs[2]); + assert_eq!(p_ltr.direction(), Direction::Ltr); + assert_eq!(p_rtl.direction(), Direction::Rtl); + assert_eq!(p_mixed.direction(), Direction::Mixed); + } + + #[test] + fn test_edge_cases_direction() { + // No paragraphs for empty text. + let empty = ""; + let bidi_info = BidiInfo::new(empty, Option::from(RTL_LEVEL)); + assert_eq!(bidi_info.paragraphs.len(), 0); + + let empty = &to_utf16(empty); + let bidi_info = BidiInfoU16::new(empty, Option::from(RTL_LEVEL)); + assert_eq!(bidi_info.paragraphs.len(), 0); + + let tests = vec![ + // The paragraph separator will take the value of the default direction + // which is left to right. + ("\n", None, Direction::Ltr), + // The paragraph separator will take the value of the given initial direction + // which is left to right. + ("\n", Option::from(LTR_LEVEL), Direction::Ltr), + // The paragraph separator will take the value of the given initial direction + // which is right to left. + ("\n", Option::from(RTL_LEVEL), Direction::Rtl), + ]; + + for t in tests { + let bidi_info = BidiInfo::new(t.0, t.1); + assert_eq!(bidi_info.paragraphs.len(), 1); + let p = Paragraph::new(&bidi_info, &bidi_info.paragraphs[0]); + assert_eq!(p.direction(), t.2); + let text = &to_utf16(t.0); + let bidi_info = BidiInfoU16::new(text, t.1); + let p = ParagraphU16::new(&bidi_info, &bidi_info.paragraphs[0]); + assert_eq!(p.direction(), t.2); + } + } + + #[test] + fn test_level_at() { + let ltr_text = "hello world"; + let rtl_text = "أهلا بكم"; + let all_paragraphs = format!("{}\n{}\n{}{}", ltr_text, rtl_text, ltr_text, rtl_text); + let bidi_info = BidiInfo::new(&all_paragraphs, None); + assert_eq!(bidi_info.paragraphs.len(), 3); + + let p_ltr = Paragraph::new(&bidi_info, &bidi_info.paragraphs[0]); + let p_rtl = Paragraph::new(&bidi_info, &bidi_info.paragraphs[1]); + let p_mixed = Paragraph::new(&bidi_info, &bidi_info.paragraphs[2]); + + assert_eq!(p_ltr.level_at(0), LTR_LEVEL); + assert_eq!(p_rtl.level_at(0), RTL_LEVEL); + assert_eq!(p_mixed.level_at(0), LTR_LEVEL); + assert_eq!(p_mixed.info.levels.len(), 54); + assert_eq!(p_mixed.para.range.start, 28); + assert_eq!(p_mixed.level_at(ltr_text.len()), RTL_LEVEL); + + let all_paragraphs = &to_utf16(&all_paragraphs); + let bidi_info = BidiInfoU16::new(&all_paragraphs, None); + assert_eq!(bidi_info.paragraphs.len(), 3); + + let p_ltr = ParagraphU16::new(&bidi_info, &bidi_info.paragraphs[0]); + let p_rtl = ParagraphU16::new(&bidi_info, &bidi_info.paragraphs[1]); + let p_mixed = ParagraphU16::new(&bidi_info, &bidi_info.paragraphs[2]); + + assert_eq!(p_ltr.level_at(0), LTR_LEVEL); + assert_eq!(p_rtl.level_at(0), RTL_LEVEL); + assert_eq!(p_mixed.level_at(0), LTR_LEVEL); + assert_eq!(p_mixed.info.levels.len(), 40); + assert_eq!(p_mixed.para.range.start, 21); + assert_eq!(p_mixed.level_at(ltr_text.len()), RTL_LEVEL); + } + + #[test] + fn test_get_base_direction() { + let tests = vec![ + ("", Direction::Mixed), // return Mixed if no strong character found + ("123[]-+\u{2019}\u{2060}\u{00bf}?", Direction::Mixed), + ("3.14\npi", Direction::Mixed), // only first paragraph is considered + ("[123 'abc']", Direction::Ltr), + ("[123 '\u{0628}' abc", Direction::Rtl), + ("[123 '\u{2066}abc\u{2069}'\u{0628}]", Direction::Rtl), // embedded isolate is ignored + ("[123 '\u{2066}abc\u{2068}'\u{0628}]", Direction::Mixed), + ]; + + for t in tests { + assert_eq!(get_base_direction(t.0), t.1); + let text = &to_utf16(t.0); + assert_eq!(get_base_direction(text.as_slice()), t.1); + } + } + + #[test] + fn test_get_base_direction_full() { + let tests = vec![ + ("", Direction::Mixed), // return Mixed if no strong character found + ("123[]-+\u{2019}\u{2060}\u{00bf}?", Direction::Mixed), + ("3.14\npi", Direction::Ltr), // direction taken from the second paragraph + ("3.14\n\u{05D0}", Direction::Rtl), // direction taken from the second paragraph + ("[123 'abc']", Direction::Ltr), + ("[123 '\u{0628}' abc", Direction::Rtl), + ("[123 '\u{2066}abc\u{2069}'\u{0628}]", Direction::Rtl), // embedded isolate is ignored + ("[123 '\u{2066}abc\u{2068}'\u{0628}]", Direction::Mixed), + ("[123 '\u{2066}abc\u{2068}'\n\u{0628}]", Direction::Rtl), // \n resets embedding level + ]; + + for t in tests { + assert_eq!(get_base_direction_full(t.0), t.1); + let text = &to_utf16(t.0); + assert_eq!(get_base_direction_full(text.as_slice()), t.1); + } + } +} + +#[cfg(all(feature = "serde", feature = "hardcoded-data", test))] +mod serde_tests { + use super::*; + use serde_test::{assert_tokens, Token}; + + #[test] + fn test_levels() { + let text = "abc אבג"; + let bidi_info = BidiInfo::new(text, None); + let levels = bidi_info.levels; + assert_eq!(text.as_bytes().len(), 10); + assert_eq!(levels.len(), 10); + assert_tokens( + &levels, + &[ + Token::Seq { len: Some(10) }, + Token::NewtypeStruct { name: "Level" }, + Token::U8(0), + Token::NewtypeStruct { name: "Level" }, + Token::U8(0), + Token::NewtypeStruct { name: "Level" }, + Token::U8(0), + Token::NewtypeStruct { name: "Level" }, + Token::U8(0), + Token::NewtypeStruct { name: "Level" }, + Token::U8(1), + Token::NewtypeStruct { name: "Level" }, + Token::U8(1), + Token::NewtypeStruct { name: "Level" }, + Token::U8(1), + Token::NewtypeStruct { name: "Level" }, + Token::U8(1), + Token::NewtypeStruct { name: "Level" }, + Token::U8(1), + Token::NewtypeStruct { name: "Level" }, + Token::U8(1), + Token::SeqEnd, + ], + ); + } +} |