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// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
use crate::complex::*;
use crate::indices::*;
use crate::provider::*;
use crate::SegmenterError;
use alloc::string::String;
use alloc::vec;
use alloc::vec::Vec;
use core::char;
use core::str::CharIndices;
use icu_provider::prelude::*;
use utf8_iter::Utf8CharIndices;
// TODO(#1637): These constants should be data driven.
#[allow(dead_code)]
const UNKNOWN: u8 = 0;
#[allow(dead_code)]
const AI: u8 = 1;
#[allow(dead_code)]
const AL: u8 = 2;
#[allow(dead_code)]
const B2: u8 = 3;
#[allow(dead_code)]
const BA: u8 = 4;
#[allow(dead_code)]
const BB: u8 = 5;
#[allow(dead_code)]
const BK: u8 = 6;
#[allow(dead_code)]
const CB: u8 = 7;
#[allow(dead_code)]
const CJ: u8 = 8;
#[allow(dead_code)]
const CL: u8 = 9;
#[allow(dead_code)]
const CM: u8 = 10;
#[allow(dead_code)]
const CP: u8 = 11;
#[allow(dead_code)]
const CR: u8 = 12;
#[allow(dead_code)]
const EB: u8 = 13;
#[allow(dead_code)]
const EM: u8 = 14;
#[allow(dead_code)]
const EX: u8 = 15;
#[allow(dead_code)]
const GL: u8 = 16;
#[allow(dead_code)]
const H2: u8 = 17;
#[allow(dead_code)]
const H3: u8 = 18;
#[allow(dead_code)]
const HL: u8 = 19;
#[allow(dead_code)]
const HY: u8 = 20;
#[allow(dead_code)]
const ID: u8 = 21;
#[allow(dead_code)]
const ID_CN: u8 = 22;
#[allow(dead_code)]
const IN: u8 = 23;
#[allow(dead_code)]
const IS: u8 = 24;
#[allow(dead_code)]
const JL: u8 = 25;
#[allow(dead_code)]
const JT: u8 = 26;
#[allow(dead_code)]
const JV: u8 = 27;
#[allow(dead_code)]
const LF: u8 = 28;
#[allow(dead_code)]
const NL: u8 = 29;
#[allow(dead_code)]
const NS: u8 = 30;
#[allow(dead_code)]
const NU: u8 = 31;
#[allow(dead_code)]
const OP_EA: u8 = 32;
#[allow(dead_code)]
const OP_OP30: u8 = 33;
#[allow(dead_code)]
const PO: u8 = 34;
#[allow(dead_code)]
const PO_EAW: u8 = 35;
#[allow(dead_code)]
const PR: u8 = 36;
#[allow(dead_code)]
const PR_EAW: u8 = 37;
#[allow(dead_code)]
const QU: u8 = 38;
#[allow(dead_code)]
const RI: u8 = 39;
#[allow(dead_code)]
const SA: u8 = 40;
#[allow(dead_code)]
const SG: u8 = 41;
#[allow(dead_code)]
const SP: u8 = 42;
#[allow(dead_code)]
const SY: u8 = 43;
#[allow(dead_code)]
const WJ: u8 = 44;
#[allow(dead_code)]
const XX: u8 = 45;
#[allow(dead_code)]
const ZW: u8 = 46;
#[allow(dead_code)]
const ZWJ: u8 = 47;
/// An enum specifies the strictness of line-breaking rules. It can be passed as
/// an argument when creating a line segmenter.
///
/// Each enum value has the same meaning with respect to the `line-break`
/// property values in the CSS Text spec. See the details in
#[non_exhaustive]
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub enum LineBreakStrictness {
/// Breaks text using the least restrictive set of line-breaking rules.
/// Typically used for short lines, such as in newspapers.
Loose,
/// Breaks text using the most common set of line-breaking rules.
Normal,
/// Breaks text using the most stringent set of line-breaking rules.
///
/// This is the default behaviour of the Unicode Line Breaking Algorithm,
Strict,
/// Breaks text assuming there is a soft wrap opportunity around every
/// typographic character unit, disregarding any prohibition against line
/// breaks. See more details in
Anywhere,
}
/// An enum specifies the line break opportunities between letters. It can be
/// passed as an argument when creating a line segmenter.
///
/// Each enum value has the same meaning with respect to the `word-break`
/// property values in the CSS Text spec. See the details in
#[non_exhaustive]
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub enum LineBreakWordOption {
/// Words break according to their customary rules. See the details in
Normal,
/// Breaking is allowed within "words".
BreakAll,
/// Breaking is forbidden within "word".
KeepAll,
}
/// Options to tailor line-breaking behavior.
#[non_exhaustive]
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub struct LineBreakOptions {
/// Strictness of line-breaking rules. See [`LineBreakStrictness`].
pub strictness: LineBreakStrictness,
/// Line break opportunities between letters. See [`LineBreakWordOption`].
pub word_option: LineBreakWordOption,
/// Use `true` as a hint to the line segmenter that the writing
/// system is Chinese or Japanese. This allows more break opportunities when
/// `LineBreakStrictness` is `Normal` or `Loose`. See
///
/// This option has no effect in Latin-1 mode.
pub ja_zh: bool,
}
impl Default for LineBreakOptions {
fn default() -> Self {
Self {
strictness: LineBreakStrictness::Strict,
word_option: LineBreakWordOption::Normal,
ja_zh: false,
}
}
}
/// Line break iterator for an `str` (a UTF-8 string).
///
/// For examples of use, see [`LineSegmenter`].
pub type LineBreakIteratorUtf8<'l, 's> = LineBreakIterator<'l, 's, LineBreakTypeUtf8>;
/// Line break iterator for a potentially invalid UTF-8 string.
///
/// For examples of use, see [`LineSegmenter`].
pub type LineBreakIteratorPotentiallyIllFormedUtf8<'l, 's> =
LineBreakIterator<'l, 's, LineBreakTypePotentiallyIllFormedUtf8>;
/// Line break iterator for a Latin-1 (8-bit) string.
///
/// For examples of use, see [`LineSegmenter`].
pub type LineBreakIteratorLatin1<'l, 's> = LineBreakIterator<'l, 's, LineBreakTypeLatin1>;
/// Line break iterator for a UTF-16 string.
///
/// For examples of use, see [`LineSegmenter`].
pub type LineBreakIteratorUtf16<'l, 's> = LineBreakIterator<'l, 's, LineBreakTypeUtf16>;
/// Supports loading line break data, and creating line break iterators for different string
/// encodings.
///
/// The segmenter returns mandatory breaks (as defined by [definition LD7][LD7] of
/// Unicode Standard Annex #14, _Unicode Line Breaking Algorithm_) as well as
/// line break opportunities ([definition LD3][LD3]).
/// It does not distinguish them. Callers requiring that distinction can check
/// the Line_Break property of the code point preceding the break against those
/// listed in rules [LB4][LB4] and [LB5][LB5], special-casing the end of text
/// according to [LB3][LB3].
///
/// For consistency with the grapheme, word, and sentence segmenters, there is
/// always a breakpoint returned at index 0, but this breakpoint is not a
/// meaningful line break opportunity.
///
///
/// ```rust
/// # use icu::segmenter::LineSegmenter;
/// #
/// # let segmenter = LineSegmenter::new_auto();
/// #
/// let text = "Summary\r\nThis annex…";
/// let breakpoints: Vec<usize> = segmenter.segment_str(text).collect();
/// // 9 and 22 are mandatory breaks, 14 is a line break opportunity.
/// assert_eq!(&breakpoints, &[0, 9, 14, 22]);
///
/// // There is a break opportunity between emoji, but not within the ZWJ sequence 🏳️🌈.
/// let flag_equation = "🏳️➕🌈🟰🏳️\u{200D}🌈";
/// let possible_first_lines: Vec<&str> =
/// segmenter.segment_str(flag_equation).skip(1).map(|i| &flag_equation[..i]).collect();
/// assert_eq!(
/// &possible_first_lines,
/// &[
/// "🏳️",
/// "🏳️➕",
/// "🏳️➕🌈",
/// "🏳️➕🌈🟰",
/// "🏳️➕🌈🟰🏳️🌈"
/// ]
/// );
/// ```
///
/// # Examples
///
/// Segment a string with default options:
///
/// ```rust
/// use icu::segmenter::LineSegmenter;
///
/// let segmenter = LineSegmenter::new_auto();
///
/// let breakpoints: Vec<usize> =
/// segmenter.segment_str("Hello World").collect();
/// assert_eq!(&breakpoints, &[0, 6, 11]);
/// ```
///
/// Segment a string with CSS option overrides:
///
/// ```rust
/// use icu::segmenter::{
/// LineBreakOptions, LineBreakStrictness, LineBreakWordOption,
/// LineSegmenter,
/// };
///
/// let mut options = LineBreakOptions::default();
/// options.strictness = LineBreakStrictness::Strict;
/// options.word_option = LineBreakWordOption::BreakAll;
/// options.ja_zh = false;
/// let segmenter = LineSegmenter::new_auto_with_options(options);
///
/// let breakpoints: Vec<usize> =
/// segmenter.segment_str("Hello World").collect();
/// assert_eq!(&breakpoints, &[0, 1, 2, 3, 4, 6, 7, 8, 9, 10, 11]);
/// ```
///
/// Segment a Latin1 byte string:
///
/// ```rust
/// use icu::segmenter::LineSegmenter;
///
/// let segmenter = LineSegmenter::new_auto();
///
/// let breakpoints: Vec<usize> =
/// segmenter.segment_latin1(b"Hello World").collect();
/// assert_eq!(&breakpoints, &[0, 6, 11]);
/// ```
///
/// Separate mandatory breaks from the break opportunities:
///
/// ```rust
/// use icu::properties::{maps, LineBreak};
/// use icu::segmenter::LineSegmenter;
///
/// # let segmenter = LineSegmenter::new_auto();
/// #
/// let text = "Summary\r\nThis annex…";
///
/// let mandatory_breaks: Vec<usize> = segmenter
/// .segment_str(text)
/// .into_iter()
/// .filter(|&i| {
/// text[..i].chars().next_back().map_or(false, |c| {
/// matches!(
/// maps::line_break().get(c),
/// LineBreak::MandatoryBreak
/// | LineBreak::CarriageReturn
/// | LineBreak::LineFeed
/// | LineBreak::NextLine
/// ) || i == text.len()
/// })
/// })
/// .collect();
/// assert_eq!(&mandatory_breaks, &[9, 22]);
/// ```
#[derive(Debug)]
pub struct LineSegmenter {
options: LineBreakOptions,
payload: DataPayload<LineBreakDataV1Marker>,
complex: ComplexPayloads,
}
impl LineSegmenter {
/// Constructs a [`LineSegmenter`] with an invariant locale and the best available compiled data for
/// complex scripts (Khmer, Lao, Myanmar, and Thai).
///
/// The current behavior, which is subject to change, is to use the LSTM model when available.
///
/// See also [`Self::new_auto_with_options`].
///
/// ✨ *Enabled with the `compiled_data` and `auto` Cargo features.*
///
/// [📚 Help choosing a constructor](icu_provider::constructors)
#[cfg(feature = "compiled_data")]
#[cfg(feature = "auto")]
pub fn new_auto() -> Self {
Self::new_auto_with_options(Default::default())
}
#[cfg(feature = "auto")]
icu_provider::gen_any_buffer_data_constructors!(
locale: skip,
options: skip,
error: SegmenterError,
#[cfg(skip)]
functions: [
new_auto,
try_new_auto_with_any_provider,
try_new_auto_with_buffer_provider,
try_new_auto_unstable,
Self,
]
);
#[doc = icu_provider::gen_any_buffer_unstable_docs!(UNSTABLE, Self::new_auto)]
#[cfg(feature = "auto")]
pub fn try_new_auto_unstable<D>(provider: &D) -> Result<Self, SegmenterError>
where
D: DataProvider<LineBreakDataV1Marker>
+ DataProvider<LstmForWordLineAutoV1Marker>
+ DataProvider<GraphemeClusterBreakDataV1Marker>
+ ?Sized,
{
Self::try_new_auto_with_options_unstable(provider, Default::default())
}
/// Constructs a [`LineSegmenter`] with an invariant locale and compiled LSTM data for
/// complex scripts (Khmer, Lao, Myanmar, and Thai).
///
/// The LSTM, or Long Term Short Memory, is a machine learning model. It is smaller than
/// the full dictionary but more expensive during segmentation (inference).
///
/// See also [`Self::new_lstm_with_options`].
///
/// ✨ *Enabled with the `compiled_data` and `lstm` Cargo features.*
///
/// [📚 Help choosing a constructor](icu_provider::constructors)
#[cfg(feature = "compiled_data")]
#[cfg(feature = "lstm")]
pub fn new_lstm() -> Self {
Self::new_lstm_with_options(Default::default())
}
#[cfg(feature = "lstm")]
icu_provider::gen_any_buffer_data_constructors!(
locale: skip,
options: skip,
error: SegmenterError,
#[cfg(skip)]
functions: [
new_lstm,
try_new_lstm_with_any_provider,
try_new_lstm_with_buffer_provider,
try_new_lstm_unstable,
Self,
]
);
#[cfg(feature = "lstm")]
#[doc = icu_provider::gen_any_buffer_unstable_docs!(UNSTABLE, Self::new_lstm)]
pub fn try_new_lstm_unstable<D>(provider: &D) -> Result<Self, SegmenterError>
where
D: DataProvider<LineBreakDataV1Marker>
+ DataProvider<LstmForWordLineAutoV1Marker>
+ DataProvider<GraphemeClusterBreakDataV1Marker>
+ ?Sized,
{
Self::try_new_lstm_with_options_unstable(provider, Default::default())
}
/// Constructs a [`LineSegmenter`] with an invariant locale and compiled dictionary data for
/// complex scripts (Khmer, Lao, Myanmar, and Thai).
///
/// The dictionary model uses a list of words to determine appropriate breakpoints. It is
/// faster than the LSTM model but requires more data.
///
/// See also [`Self::new_dictionary_with_options`].
///
/// ✨ *Enabled with the `compiled_data` Cargo feature.*
///
/// [📚 Help choosing a constructor](icu_provider::constructors)
#[cfg(feature = "compiled_data")]
pub fn new_dictionary() -> Self {
Self::new_dictionary_with_options(Default::default())
}
icu_provider::gen_any_buffer_data_constructors!(
locale: skip,
options: skip,
error: SegmenterError,
#[cfg(skip)]
functions: [
new_dictionary,
try_new_dictionary_with_any_provider,
try_new_dictionary_with_buffer_provider,
try_new_dictionary_unstable,
Self,
]
);
#[doc = icu_provider::gen_any_buffer_unstable_docs!(UNSTABLE, Self::new_dictionary)]
pub fn try_new_dictionary_unstable<D>(provider: &D) -> Result<Self, SegmenterError>
where
D: DataProvider<LineBreakDataV1Marker>
+ DataProvider<DictionaryForWordLineExtendedV1Marker>
+ DataProvider<GraphemeClusterBreakDataV1Marker>
+ ?Sized,
{
Self::try_new_dictionary_with_options_unstable(provider, Default::default())
}
/// Constructs a [`LineSegmenter`] with an invariant locale, custom [`LineBreakOptions`], and
/// the best available compiled data for complex scripts (Khmer, Lao, Myanmar, and Thai).
///
/// The current behavior, which is subject to change, is to use the LSTM model when available.
///
/// See also [`Self::new_auto`].
///
/// ✨ *Enabled with the `compiled_data` and `auto` Cargo features.*
///
/// [📚 Help choosing a constructor](icu_provider::constructors)
#[cfg(feature = "auto")]
#[cfg(feature = "compiled_data")]
pub fn new_auto_with_options(options: LineBreakOptions) -> Self {
Self::new_lstm_with_options(options)
}
#[cfg(feature = "auto")]
icu_provider::gen_any_buffer_data_constructors!(
locale: skip,
options: LineBreakOptions,
error: SegmenterError,
#[cfg(skip)]
functions: [
new_auto_with_options,
try_new_auto_with_options_with_any_provider,
try_new_auto_with_options_with_buffer_provider,
try_new_auto_with_options_unstable,
Self,
]
);
#[cfg(feature = "auto")]
#[doc = icu_provider::gen_any_buffer_unstable_docs!(UNSTABLE, Self::new_auto_with_options)]
pub fn try_new_auto_with_options_unstable<D>(
provider: &D,
options: LineBreakOptions,
) -> Result<Self, SegmenterError>
where
D: DataProvider<LineBreakDataV1Marker>
+ DataProvider<LstmForWordLineAutoV1Marker>
+ DataProvider<GraphemeClusterBreakDataV1Marker>
+ ?Sized,
{
Self::try_new_lstm_with_options_unstable(provider, options)
}
/// Constructs a [`LineSegmenter`] with an invariant locale, custom [`LineBreakOptions`], and
/// compiled LSTM data for complex scripts (Khmer, Lao, Myanmar, and Thai).
///
/// The LSTM, or Long Term Short Memory, is a machine learning model. It is smaller than
/// the full dictionary but more expensive during segmentation (inference).
///
/// See also [`Self::new_dictionary`].
///
/// ✨ *Enabled with the `compiled_data` and `lstm` Cargo features.*
///
/// [📚 Help choosing a constructor](icu_provider::constructors)
#[cfg(feature = "lstm")]
#[cfg(feature = "compiled_data")]
pub fn new_lstm_with_options(options: LineBreakOptions) -> Self {
Self {
options,
payload: DataPayload::from_static_ref(
crate::provider::Baked::SINGLETON_SEGMENTER_LINE_V1,
),
complex: ComplexPayloads::new_lstm(),
}
}
#[cfg(feature = "lstm")]
icu_provider::gen_any_buffer_data_constructors!(
locale: skip,
options: LineBreakOptions,
error: SegmenterError,
#[cfg(skip)]
functions: [
try_new_lstm_with_options,
try_new_lstm_with_options_with_any_provider,
try_new_lstm_with_options_with_buffer_provider,
try_new_lstm_with_options_unstable,
Self,
]
);
#[cfg(feature = "lstm")]
#[doc = icu_provider::gen_any_buffer_unstable_docs!(UNSTABLE, Self::new_lstm_with_options)]
pub fn try_new_lstm_with_options_unstable<D>(
provider: &D,
options: LineBreakOptions,
) -> Result<Self, SegmenterError>
where
D: DataProvider<LineBreakDataV1Marker>
+ DataProvider<LstmForWordLineAutoV1Marker>
+ DataProvider<GraphemeClusterBreakDataV1Marker>
+ ?Sized,
{
Ok(Self {
options,
payload: provider.load(Default::default())?.take_payload()?,
complex: ComplexPayloads::try_new_lstm(provider)?,
})
}
/// Constructs a [`LineSegmenter`] with an invariant locale, custom [`LineBreakOptions`], and
/// compiled dictionary data for complex scripts (Khmer, Lao, Myanmar, and Thai).
///
/// The dictionary model uses a list of words to determine appropriate breakpoints. It is
/// faster than the LSTM model but requires more data.
///
/// See also [`Self::new_dictionary`].
///
/// ✨ *Enabled with the `compiled_data` Cargo feature.*
///
/// [📚 Help choosing a constructor](icu_provider::constructors)
#[cfg(feature = "compiled_data")]
pub fn new_dictionary_with_options(options: LineBreakOptions) -> Self {
Self {
options,
payload: DataPayload::from_static_ref(
crate::provider::Baked::SINGLETON_SEGMENTER_LINE_V1,
),
// Line segmenter doesn't need to load CJ dictionary because UAX 14 rules handles CJK
// characters [1]. Southeast Asian languages however require complex context analysis
// [2].
//
complex: ComplexPayloads::new_southeast_asian(),
}
}
icu_provider::gen_any_buffer_data_constructors!(
locale: skip,
options: LineBreakOptions,
error: SegmenterError,
#[cfg(skip)]
functions: [
new_dictionary_with_options,
try_new_dictionary_with_options_with_any_provider,
try_new_dictionary_with_options_with_buffer_provider,
try_new_dictionary_with_options_unstable,
Self,
]
);
#[doc = icu_provider::gen_any_buffer_unstable_docs!(UNSTABLE, Self::new_dictionary_with_options)]
pub fn try_new_dictionary_with_options_unstable<D>(
provider: &D,
options: LineBreakOptions,
) -> Result<Self, SegmenterError>
where
D: DataProvider<LineBreakDataV1Marker>
+ DataProvider<DictionaryForWordLineExtendedV1Marker>
+ DataProvider<GraphemeClusterBreakDataV1Marker>
+ ?Sized,
{
Ok(Self {
options,
payload: provider.load(Default::default())?.take_payload()?,
// Line segmenter doesn't need to load CJ dictionary because UAX 14 rules handles CJK
// characters [1]. Southeast Asian languages however require complex context analysis
// [2].
//
complex: ComplexPayloads::try_new_southeast_asian(provider)?,
})
}
/// Creates a line break iterator for an `str` (a UTF-8 string).
///
/// There are always breakpoints at 0 and the string length, or only at 0 for the empty string.
pub fn segment_str<'l, 's>(&'l self, input: &'s str) -> LineBreakIteratorUtf8<'l, 's> {
LineBreakIterator {
iter: input.char_indices(),
len: input.len(),
current_pos_data: None,
result_cache: Vec::new(),
data: self.payload.get(),
options: &self.options,
complex: &self.complex,
}
}
/// Creates a line break iterator for a potentially ill-formed UTF8 string
///
/// Invalid characters are treated as REPLACEMENT CHARACTER
///
/// There are always breakpoints at 0 and the string length, or only at 0 for the empty string.
pub fn segment_utf8<'l, 's>(
&'l self,
input: &'s [u8],
) -> LineBreakIteratorPotentiallyIllFormedUtf8<'l, 's> {
LineBreakIterator {
iter: Utf8CharIndices::new(input),
len: input.len(),
current_pos_data: None,
result_cache: Vec::new(),
data: self.payload.get(),
options: &self.options,
complex: &self.complex,
}
}
/// Creates a line break iterator for a Latin-1 (8-bit) string.
///
/// There are always breakpoints at 0 and the string length, or only at 0 for the empty string.
pub fn segment_latin1<'l, 's>(&'l self, input: &'s [u8]) -> LineBreakIteratorLatin1<'l, 's> {
LineBreakIterator {
iter: Latin1Indices::new(input),
len: input.len(),
current_pos_data: None,
result_cache: Vec::new(),
data: self.payload.get(),
options: &self.options,
complex: &self.complex,
}
}
/// Creates a line break iterator for a UTF-16 string.
///
/// There are always breakpoints at 0 and the string length, or only at 0 for the empty string.
pub fn segment_utf16<'l, 's>(&'l self, input: &'s [u16]) -> LineBreakIteratorUtf16<'l, 's> {
LineBreakIterator {
iter: Utf16Indices::new(input),
len: input.len(),
current_pos_data: None,
result_cache: Vec::new(),
data: self.payload.get(),
options: &self.options,
complex: &self.complex,
}
}
}
impl RuleBreakDataV1<'_> {
fn get_linebreak_property_utf32_with_rule(
&self,
codepoint: u32,
strictness: LineBreakStrictness,
word_option: LineBreakWordOption,
) -> u8 {
// Note: Default value is 0 == UNKNOWN
let prop = self.property_table.get32(codepoint);
if word_option == LineBreakWordOption::BreakAll
|| strictness == LineBreakStrictness::Loose
|| strictness == LineBreakStrictness::Normal
{
return match prop {
CJ => ID, // All CJ's General_Category is Other_Letter (Lo).
_ => prop,
};
}
// CJ is treated as NS by default, yielding strict line breaking.
prop
}
#[inline]
fn get_break_state_from_table(&self, left: u8, right: u8) -> BreakState {
let idx = (left as usize) * (self.property_count as usize) + (right as usize);
// We use unwrap_or to fall back to the base case and prevent panics on bad data.
self.break_state_table.get(idx).unwrap_or(BreakState::Keep)
}
#[inline]
fn use_complex_breaking_utf32(&self, codepoint: u32) -> bool {
let line_break_property = self.get_linebreak_property_utf32_with_rule(
codepoint,
LineBreakStrictness::Strict,
LineBreakWordOption::Normal,
);
line_break_property == SA
}
}
#[inline]
fn is_break_utf32_by_loose(
right_codepoint: u32,
left_prop: u8,
right_prop: u8,
ja_zh: bool,
) -> Option<bool> {
// breaks before hyphens
if right_prop == BA {
if left_prop == ID && (right_codepoint == 0x2010 || right_codepoint == 0x2013) {
return Some(true);
}
} else if right_prop == NS {
// breaks before certain CJK hyphen-like characters
if right_codepoint == 0x301C || right_codepoint == 0x30A0 {
return Some(ja_zh);
}
// breaks before iteration marks
if right_codepoint == 0x3005
|| right_codepoint == 0x303B
|| right_codepoint == 0x309D
|| right_codepoint == 0x309E
|| right_codepoint == 0x30FD
|| right_codepoint == 0x30FE
{
return Some(true);
}
// breaks before certain centered punctuation marks:
if right_codepoint == 0x30FB
|| right_codepoint == 0xFF1A
|| right_codepoint == 0xFF1B
|| right_codepoint == 0xFF65
|| right_codepoint == 0x203C
|| (0x2047..=0x2049).contains(&right_codepoint)
{
return Some(ja_zh);
}
} else if right_prop == IN {
// breaks between inseparable characters such as U+2025, U+2026 i.e. characters with the Unicode Line Break property IN
return Some(true);
} else if right_prop == EX {
// breaks before certain centered punctuation marks:
if right_codepoint == 0xFF01 || right_codepoint == 0xFF1F {
return Some(ja_zh);
}
}
// breaks before suffixes:
// Characters with the Unicode Line Break property PO and the East Asian Width property
if right_prop == PO_EAW {
return Some(ja_zh);
}
// breaks after prefixes:
// Characters with the Unicode Line Break property PR and the East Asian Width property
if left_prop == PR_EAW {
return Some(ja_zh);
}
None
}
/// A trait allowing for LineBreakIterator to be generalized to multiple string iteration methods.
///
/// This is implemented by ICU4X for several common string types.
pub trait LineBreakType<'l, 's> {
/// The iterator over characters.
type IterAttr: Iterator<Item = (usize, Self::CharType)> + Clone;
/// The character type.
type CharType: Copy + Into<u32>;
fn use_complex_breaking(iterator: &LineBreakIterator<'l, 's, Self>, c: Self::CharType) -> bool;
fn get_linebreak_property_with_rule(
iterator: &LineBreakIterator<'l, 's, Self>,
c: Self::CharType,
) -> u8;
fn get_current_position_character_len(iterator: &LineBreakIterator<'l, 's, Self>) -> usize;
fn handle_complex_language(
iterator: &mut LineBreakIterator<'l, 's, Self>,
left_codepoint: Self::CharType,
) -> Option<usize>;
}
/// Implements the [`Iterator`] trait over the line break opportunities of the given string.
///
/// Lifetimes:
///
/// - `'l` = lifetime of the [`LineSegmenter`] object from which this iterator was created
/// - `'s` = lifetime of the string being segmented
///
/// The [`Iterator::Item`] is an [`usize`] representing index of a code unit
/// _after_ the break (for a break at the end of text, this index is the length
/// of the [`str`] or array of code units).
///
/// For examples of use, see [`LineSegmenter`].
#[derive(Debug)]
pub struct LineBreakIterator<'l, 's, Y: LineBreakType<'l, 's> + ?Sized> {
iter: Y::IterAttr,
len: usize,
current_pos_data: Option<(usize, Y::CharType)>,
result_cache: Vec<usize>,
data: &'l RuleBreakDataV1<'l>,
options: &'l LineBreakOptions,
complex: &'l ComplexPayloads,
}
impl<'l, 's, Y: LineBreakType<'l, 's>> Iterator for LineBreakIterator<'l, 's, Y> {
type Item = usize;
fn next(&mut self) -> Option<Self::Item> {
match self.check_eof() {
StringBoundaryPosType::Start => return Some(0),
StringBoundaryPosType::End => return None,
_ => (),
}
// If we have break point cache by previous run, return this result
if let Some(&first_pos) = self.result_cache.first() {
let mut i = 0;
loop {
if i == first_pos {
self.result_cache = self.result_cache.iter().skip(1).map(|r| r - i).collect();
return self.get_current_position();
}
i += Y::get_current_position_character_len(self);
self.advance_iter();
if self.is_eof() {
self.result_cache.clear();
return Some(self.len);
}
}
}
'a: loop {
debug_assert!(!self.is_eof());
let left_codepoint = self.get_current_codepoint()?;
let mut left_prop = self.get_linebreak_property(left_codepoint);
self.advance_iter();
let Some(right_codepoint) = self.get_current_codepoint() else {
return Some(self.len);
};
let right_prop = self.get_linebreak_property(right_codepoint);
// CSS word-break property handling
match (self.options.word_option, left_prop, right_prop) {
(LineBreakWordOption::BreakAll, AL | NU | SA, _) => {
left_prop = ID;
}
// typographic letter units shouldn't be break
(
LineBreakWordOption::KeepAll,
AI | AL | ID | NU | HY | H2 | H3 | JL | JV | JT | CJ,
AI | AL | ID | NU | HY | H2 | H3 | JL | JV | JT | CJ,
) => {
continue;
}
_ => (),
}
// CSS line-break property handling
match self.options.strictness {
LineBreakStrictness::Normal => {
if self.is_break_by_normal(right_codepoint) {
return self.get_current_position();
}
}
LineBreakStrictness::Loose => {
if let Some(breakable) = is_break_utf32_by_loose(
right_codepoint.into(),
left_prop,
right_prop,
self.options.ja_zh,
) {
if breakable {
return self.get_current_position();
}
continue;
}
}
LineBreakStrictness::Anywhere => {
return self.get_current_position();
}
_ => (),
};
// UAX14 doesn't have Thai etc, so use another way.
if self.options.word_option != LineBreakWordOption::BreakAll
&& Y::use_complex_breaking(self, left_codepoint)
&& Y::use_complex_breaking(self, right_codepoint)
{
let result = Y::handle_complex_language(self, left_codepoint);
if result.is_some() {
return result;
}
// I may have to fetch text until non-SA character?.
}
// If break_state is equals or grater than 0, it is alias of property.
let mut index = match self.data.get_break_state_from_table(left_prop, right_prop) {
BreakState::Index(index) => index,
// Line break uses more that 64 states, so they spill over into the intermediate range,
// and we cannot change that at the moment
BreakState::Intermediate(index) => index + 64,
BreakState::Break | BreakState::NoMatch => return self.get_current_position(),
BreakState::Keep => continue,
};
let mut previous_iter = self.iter.clone();
let mut previous_pos_data = self.current_pos_data;
loop {
self.advance_iter();
let Some(prop) = self.get_current_linebreak_property() else {
// Reached EOF. But we are analyzing multiple characters now, so next break may be previous point.
let break_state = self
.data
.get_break_state_from_table(index, self.data.eot_property);
if break_state == BreakState::NoMatch {
self.iter = previous_iter;
self.current_pos_data = previous_pos_data;
return self.get_current_position();
}
// EOF
return Some(self.len);
};
match self.data.get_break_state_from_table(index, prop) {
BreakState::Keep => continue 'a,
BreakState::NoMatch => {
self.iter = previous_iter;
self.current_pos_data = previous_pos_data;
return self.get_current_position();
}
BreakState::Break => return self.get_current_position(),
BreakState::Index(i) => {
index = i;
previous_iter = self.iter.clone();
previous_pos_data = self.current_pos_data;
}
BreakState::Intermediate(i) => {
index = i + 64;
previous_iter = self.iter.clone();
previous_pos_data = self.current_pos_data;
}
}
}
}
}
}
enum StringBoundaryPosType {
Start,
Middle,
End,
}
impl<'l, 's, Y: LineBreakType<'l, 's>> LineBreakIterator<'l, 's, Y> {
fn advance_iter(&mut self) {
self.current_pos_data = self.iter.next();
}
fn is_eof(&self) -> bool {
self.current_pos_data.is_none()
}
#[inline]
fn check_eof(&mut self) -> StringBoundaryPosType {
if self.is_eof() {
self.advance_iter();
if self.is_eof() {
if self.len == 0 {
// Empty string. Since `self.current_pos_data` is always going to be empty,
// we never read `self.len` except for here, so we can use it to mark that
// we have already returned the single empty-string breakpoint.
self.len = 1;
StringBoundaryPosType::Start
} else {
StringBoundaryPosType::End
}
} else {
StringBoundaryPosType::Start
}
} else {
StringBoundaryPosType::Middle
}
}
fn get_current_position(&self) -> Option<usize> {
self.current_pos_data.map(|(pos, _)| pos)
}
fn get_current_codepoint(&self) -> Option<Y::CharType> {
self.current_pos_data.map(|(_, codepoint)| codepoint)
}
fn get_linebreak_property(&self, codepoint: Y::CharType) -> u8 {
Y::get_linebreak_property_with_rule(self, codepoint)
}
fn get_current_linebreak_property(&self) -> Option<u8> {
self.get_current_codepoint()
.map(|c| self.get_linebreak_property(c))
}
fn is_break_by_normal(&self, codepoint: Y::CharType) -> bool {
match codepoint.into() {
0x301C | 0x30A0 => self.options.ja_zh,
_ => false,
}
}
}
#[derive(Debug)]
pub struct LineBreakTypeUtf8;
impl<'l, 's> LineBreakType<'l, 's> for LineBreakTypeUtf8 {
type IterAttr = CharIndices<'s>;
type CharType = char;
fn get_linebreak_property_with_rule(iterator: &LineBreakIterator<Self>, c: char) -> u8 {
iterator.data.get_linebreak_property_utf32_with_rule(
c as u32,
iterator.options.strictness,
iterator.options.word_option,
)
}
#[inline]
fn use_complex_breaking(iterator: &LineBreakIterator<Self>, c: char) -> bool {
iterator.data.use_complex_breaking_utf32(c as u32)
}
fn get_current_position_character_len(iterator: &LineBreakIterator<Self>) -> usize {
iterator.get_current_codepoint().map_or(0, |c| c.len_utf8())
}
fn handle_complex_language(
iter: &mut LineBreakIterator<'l, 's, Self>,
left_codepoint: char,
) -> Option<usize> {
handle_complex_language_utf8(iter, left_codepoint)
}
}
#[derive(Debug)]
pub struct LineBreakTypePotentiallyIllFormedUtf8;
impl<'l, 's> LineBreakType<'l, 's> for LineBreakTypePotentiallyIllFormedUtf8 {
type IterAttr = Utf8CharIndices<'s>;
type CharType = char;
fn get_linebreak_property_with_rule(iterator: &LineBreakIterator<Self>, c: char) -> u8 {
iterator.data.get_linebreak_property_utf32_with_rule(
c as u32,
iterator.options.strictness,
iterator.options.word_option,
)
}
#[inline]
fn use_complex_breaking(iterator: &LineBreakIterator<Self>, c: char) -> bool {
iterator.data.use_complex_breaking_utf32(c as u32)
}
fn get_current_position_character_len(iterator: &LineBreakIterator<Self>) -> usize {
iterator.get_current_codepoint().map_or(0, |c| c.len_utf8())
}
fn handle_complex_language(
iter: &mut LineBreakIterator<'l, 's, Self>,
left_codepoint: char,
) -> Option<usize> {
handle_complex_language_utf8(iter, left_codepoint)
}
}
/// handle_complex_language impl for UTF8 iterators
fn handle_complex_language_utf8<'l, 's, T>(
iter: &mut LineBreakIterator<'l, 's, T>,
left_codepoint: char,
) -> Option<usize>
where
T: LineBreakType<'l, 's, CharType = char>,
{
// word segmenter doesn't define break rules for some languages such as Thai.
let start_iter = iter.iter.clone();
let start_point = iter.current_pos_data;
let mut s = String::new();
s.push(left_codepoint);
loop {
debug_assert!(!iter.is_eof());
s.push(iter.get_current_codepoint()?);
iter.advance_iter();
if let Some(current_codepoint) = iter.get_current_codepoint() {
if !T::use_complex_breaking(iter, current_codepoint) {
break;
}
} else {
// EOF
break;
}
}
// Restore iterator to move to head of complex string
iter.iter = start_iter;
iter.current_pos_data = start_point;
let breaks = complex_language_segment_str(iter.complex, &s);
iter.result_cache = breaks;
let first_pos = *iter.result_cache.first()?;
let mut i = left_codepoint.len_utf8();
loop {
if i == first_pos {
// Re-calculate breaking offset
iter.result_cache = iter.result_cache.iter().skip(1).map(|r| r - i).collect();
return iter.get_current_position();
}
debug_assert!(
i < first_pos,
"we should always arrive at first_pos: near index {:?}",
iter.get_current_position()
);
i += T::get_current_position_character_len(iter);
iter.advance_iter();
if iter.is_eof() {
iter.result_cache.clear();
return Some(iter.len);
}
}
}
#[derive(Debug)]
pub struct LineBreakTypeLatin1;
impl<'l, 's> LineBreakType<'l, 's> for LineBreakTypeLatin1 {
type IterAttr = Latin1Indices<'s>;
type CharType = u8;
fn get_linebreak_property_with_rule(iterator: &LineBreakIterator<Self>, c: u8) -> u8 {
// No CJ on Latin1
// Note: Default value is 0 == UNKNOWN
iterator.data.property_table.get32(c as u32)
}
#[inline]
fn use_complex_breaking(_iterator: &LineBreakIterator<Self>, _c: u8) -> bool {
false
}
fn get_current_position_character_len(_: &LineBreakIterator<Self>) -> usize {
unreachable!()
}
fn handle_complex_language(
_: &mut LineBreakIterator<Self>,
_: Self::CharType,
) -> Option<usize> {
unreachable!()
}
}
#[derive(Debug)]
pub struct LineBreakTypeUtf16;
impl<'l, 's> LineBreakType<'l, 's> for LineBreakTypeUtf16 {
type IterAttr = Utf16Indices<'s>;
type CharType = u32;
fn get_linebreak_property_with_rule(iterator: &LineBreakIterator<Self>, c: u32) -> u8 {
iterator.data.get_linebreak_property_utf32_with_rule(
c,
iterator.options.strictness,
iterator.options.word_option,
)
}
#[inline]
fn use_complex_breaking(iterator: &LineBreakIterator<Self>, c: u32) -> bool {
iterator.data.use_complex_breaking_utf32(c)
}
fn get_current_position_character_len(iterator: &LineBreakIterator<Self>) -> usize {
match iterator.get_current_codepoint() {
None => 0,
Some(ch) if ch >= 0x10000 => 2,
_ => 1,
}
}
fn handle_complex_language(
iterator: &mut LineBreakIterator<Self>,
left_codepoint: Self::CharType,
) -> Option<usize> {
// word segmenter doesn't define break rules for some languages such as Thai.
let start_iter = iterator.iter.clone();
let start_point = iterator.current_pos_data;
let mut s = vec![left_codepoint as u16];
loop {
debug_assert!(!iterator.is_eof());
s.push(iterator.get_current_codepoint()? as u16);
iterator.advance_iter();
if let Some(current_codepoint) = iterator.get_current_codepoint() {
if !Self::use_complex_breaking(iterator, current_codepoint) {
break;
}
} else {
// EOF
break;
}
}
// Restore iterator to move to head of complex string
iterator.iter = start_iter;
iterator.current_pos_data = start_point;
let breaks = complex_language_segment_utf16(iterator.complex, &s);
iterator.result_cache = breaks;
// result_cache vector is utf-16 index that is in BMP.
let first_pos = *iterator.result_cache.first()?;
let mut i = 1;
loop {
if i == first_pos {
// Re-calculate breaking offset
iterator.result_cache = iterator
.result_cache
.iter()
.skip(1)
.map(|r| r - i)
.collect();
return iterator.get_current_position();
}
debug_assert!(
i < first_pos,
"we should always arrive at first_pos: near index {:?}",
iterator.get_current_position()
);
i += 1;
iterator.advance_iter();
if iterator.is_eof() {
iterator.result_cache.clear();
return Some(iterator.len);
}
}
}
}
#[cfg(test)]
#[cfg(feature = "serde")]
mod tests {
use super::*;
use crate::LineSegmenter;
#[test]
fn linebreak_property() {
let payload = DataProvider::<LineBreakDataV1Marker>::load(
&crate::provider::Baked,
Default::default(),
)
.expect("Loading should succeed!")
.take_payload()
.expect("Data should be present!");
let get_linebreak_property = |codepoint| {
payload.get().get_linebreak_property_utf32_with_rule(
codepoint as u32,
LineBreakStrictness::Strict,
LineBreakWordOption::Normal,
)
};
assert_eq!(get_linebreak_property('\u{0020}'), SP);
assert_eq!(get_linebreak_property('\u{0022}'), QU);
assert_eq!(get_linebreak_property('('), OP_OP30);
assert_eq!(get_linebreak_property('\u{0030}'), NU);
assert_eq!(get_linebreak_property('['), OP_OP30);
assert_eq!(get_linebreak_property('\u{1f3fb}'), EM);
assert_eq!(get_linebreak_property('\u{20000}'), ID);
assert_eq!(get_linebreak_property('\u{e0020}'), CM);
assert_eq!(get_linebreak_property('\u{3041}'), CJ);
assert_eq!(get_linebreak_property('\u{0025}'), PO);
assert_eq!(get_linebreak_property('\u{00A7}'), AI);
assert_eq!(get_linebreak_property('\u{50005}'), XX);
assert_eq!(get_linebreak_property('\u{17D6}'), NS);
assert_eq!(get_linebreak_property('\u{2014}'), B2);
}
#[test]
#[allow(clippy::bool_assert_comparison)] // clearer when we're testing bools directly
fn break_rule() {
let payload = DataProvider::<LineBreakDataV1Marker>::load(
&crate::provider::Baked,
Default::default(),
)
.expect("Loading should succeed!")
.take_payload()
.expect("Data should be present!");
let lb_data: &RuleBreakDataV1 = payload.get();
let is_break = |left, right| {
matches!(
lb_data.get_break_state_from_table(left, right),
BreakState::Break | BreakState::NoMatch
)
};
// LB4
assert_eq!(is_break(BK, AL), true);
// LB5
assert_eq!(is_break(CR, LF), false);
assert_eq!(is_break(CR, AL), true);
assert_eq!(is_break(LF, AL), true);
assert_eq!(is_break(NL, AL), true);
// LB6
assert_eq!(is_break(AL, BK), false);
assert_eq!(is_break(AL, CR), false);
assert_eq!(is_break(AL, LF), false);
assert_eq!(is_break(AL, NL), false);
// LB7
assert_eq!(is_break(AL, SP), false);
assert_eq!(is_break(AL, ZW), false);
// LB8
// LB8a
assert_eq!(is_break(ZWJ, AL), false);
// LB9
assert_eq!(is_break(AL, ZWJ), false);
assert_eq!(is_break(AL, CM), false);
assert_eq!(is_break(ID, ZWJ), false);
// LB10
assert_eq!(is_break(ZWJ, SP), false);
assert_eq!(is_break(SP, CM), true);
// LB11
assert_eq!(is_break(AL, WJ), false);
assert_eq!(is_break(WJ, AL), false);
// LB12
assert_eq!(is_break(GL, AL), false);
// LB12a
assert_eq!(is_break(AL, GL), false);
assert_eq!(is_break(SP, GL), true);
// LB13
assert_eq!(is_break(AL, CL), false);
assert_eq!(is_break(AL, CP), false);
assert_eq!(is_break(AL, EX), false);
assert_eq!(is_break(AL, IS), false);
assert_eq!(is_break(AL, SY), false);
// LB18
assert_eq!(is_break(SP, AL), true);
// LB19
assert_eq!(is_break(AL, QU), false);
assert_eq!(is_break(QU, AL), false);
// LB20
assert_eq!(is_break(AL, CB), true);
assert_eq!(is_break(CB, AL), true);
// LB20
assert_eq!(is_break(AL, BA), false);
assert_eq!(is_break(AL, HY), false);
assert_eq!(is_break(AL, NS), false);
// LB21
assert_eq!(is_break(AL, BA), false);
assert_eq!(is_break(BB, AL), false);
assert_eq!(is_break(ID, BA), false);
assert_eq!(is_break(ID, NS), false);
// LB21a
// LB21b
assert_eq!(is_break(SY, HL), false);
// LB22
assert_eq!(is_break(AL, IN), false);
// LB 23
assert_eq!(is_break(AL, NU), false);
assert_eq!(is_break(HL, NU), false);
// LB 23a
assert_eq!(is_break(PR, ID), false);
assert_eq!(is_break(PR, EB), false);
assert_eq!(is_break(PR, EM), false);
assert_eq!(is_break(ID, PO), false);
assert_eq!(is_break(EB, PO), false);
assert_eq!(is_break(EM, PO), false);
// LB26
assert_eq!(is_break(JL, JL), false);
assert_eq!(is_break(JL, JV), false);
assert_eq!(is_break(JL, H2), false);
// LB27
assert_eq!(is_break(JL, IN), false);
assert_eq!(is_break(JL, PO), false);
assert_eq!(is_break(PR, JL), false);
// LB28
assert_eq!(is_break(AL, AL), false);
assert_eq!(is_break(HL, AL), false);
// LB29
assert_eq!(is_break(IS, AL), false);
assert_eq!(is_break(IS, HL), false);
// LB30b
assert_eq!(is_break(EB, EM), false);
// LB31
assert_eq!(is_break(ID, ID), true);
}
#[test]
fn linebreak() {
let segmenter = LineSegmenter::try_new_dictionary_unstable(&crate::provider::Baked)
.expect("Data exists");
let mut iter = segmenter.segment_str("hello world");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(6), iter.next());
assert_eq!(Some(11), iter.next());
assert_eq!(None, iter.next());
iter = segmenter.segment_str("$10 $10");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(4), iter.next());
assert_eq!(Some(7), iter.next());
assert_eq!(None, iter.next());
// LB10
// LB14
iter = segmenter.segment_str("[ abc def");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(7), iter.next());
assert_eq!(Some(10), iter.next());
assert_eq!(None, iter.next());
let input: [u8; 10] = [0x5B, 0x20, 0x20, 0x61, 0x62, 0x63, 0x20, 0x64, 0x65, 0x66];
let mut iter_u8 = segmenter.segment_latin1(&input);
assert_eq!(Some(0), iter_u8.next());
assert_eq!(Some(7), iter_u8.next());
assert_eq!(Some(10), iter_u8.next());
assert_eq!(None, iter_u8.next());
let input: [u16; 10] = [0x5B, 0x20, 0x20, 0x61, 0x62, 0x63, 0x20, 0x64, 0x65, 0x66];
let mut iter_u16 = segmenter.segment_utf16(&input);
assert_eq!(Some(0), iter_u16.next());
assert_eq!(Some(7), iter_u16.next());
assert_eq!(Some(10), iter_u16.next());
assert_eq!(None, iter_u16.next());
// LB15
iter = segmenter.segment_str("abc\u{0022} (def");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(10), iter.next());
assert_eq!(None, iter.next());
let input: [u8; 10] = [0x61, 0x62, 0x63, 0x22, 0x20, 0x20, 0x28, 0x64, 0x65, 0x66];
let mut iter_u8 = segmenter.segment_latin1(&input);
assert_eq!(Some(0), iter_u8.next());
assert_eq!(Some(10), iter_u8.next());
assert_eq!(None, iter_u8.next());
let input: [u16; 10] = [0x61, 0x62, 0x63, 0x22, 0x20, 0x20, 0x28, 0x64, 0x65, 0x66];
let mut iter_u16 = segmenter.segment_utf16(&input);
assert_eq!(Some(0), iter_u16.next());
assert_eq!(Some(10), iter_u16.next());
assert_eq!(None, iter_u16.next());
// LB16
iter = segmenter.segment_str("\u{0029}\u{203C}");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(4), iter.next());
assert_eq!(None, iter.next());
iter = segmenter.segment_str("\u{0029} \u{203C}");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(6), iter.next());
assert_eq!(None, iter.next());
let input: [u16; 4] = [0x29, 0x20, 0x20, 0x203c];
let mut iter_u16 = segmenter.segment_utf16(&input);
assert_eq!(Some(0), iter_u16.next());
assert_eq!(Some(4), iter_u16.next());
assert_eq!(None, iter_u16.next());
// LB17
iter = segmenter.segment_str("\u{2014}\u{2014}aa");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(6), iter.next());
assert_eq!(Some(8), iter.next());
assert_eq!(None, iter.next());
iter = segmenter.segment_str("\u{2014} \u{2014}aa");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(8), iter.next());
assert_eq!(Some(10), iter.next());
assert_eq!(None, iter.next());
iter = segmenter.segment_str("\u{2014}\u{2014} \u{2014}\u{2014}123 abc");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(14), iter.next());
assert_eq!(Some(18), iter.next());
assert_eq!(Some(21), iter.next());
assert_eq!(None, iter.next());
// LB25
let mut iter = segmenter.segment_str("(0,1)+(2,3)");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(11), iter.next());
assert_eq!(None, iter.next());
let input: [u16; 11] = [
0x28, 0x30, 0x2C, 0x31, 0x29, 0x2B, 0x28, 0x32, 0x2C, 0x33, 0x29,
];
let mut iter_u16 = segmenter.segment_utf16(&input);
assert_eq!(Some(0), iter_u16.next());
assert_eq!(Some(11), iter_u16.next());
assert_eq!(None, iter_u16.next());
let input: [u16; 13] = [
0x2014, 0x2014, 0x20, 0x20, 0x2014, 0x2014, 0x31, 0x32, 0x33, 0x20, 0x61, 0x62, 0x63,
];
let mut iter_u16 = segmenter.segment_utf16(&input);
assert_eq!(Some(0), iter_u16.next());
assert_eq!(Some(6), iter_u16.next());
assert_eq!(Some(10), iter_u16.next());
assert_eq!(Some(13), iter_u16.next());
assert_eq!(None, iter_u16.next());
iter = segmenter.segment_str("\u{1F3FB} \u{1F3FB}");
assert_eq!(Some(0), iter.next());
assert_eq!(Some(5), iter.next());
assert_eq!(Some(9), iter.next());
assert_eq!(None, iter.next());
}
#[test]
#[cfg(feature = "lstm")]
fn thai_line_break() {
const TEST_STR: &str = "ภาษาไทยภาษาไทย";
let segmenter = LineSegmenter::new_lstm();
let breaks: Vec<usize> = segmenter.segment_str(TEST_STR).collect();
assert_eq!(breaks, [0, 12, 21, 33, TEST_STR.len()], "Thai test");
let utf16: Vec<u16> = TEST_STR.encode_utf16().collect();
let breaks: Vec<usize> = segmenter.segment_utf16(&utf16).collect();
assert_eq!(breaks, [0, 4, 7, 11, utf16.len()], "Thai test");
let utf16: [u16; 4] = [0x0e20, 0x0e32, 0x0e29, 0x0e32];
let breaks: Vec<usize> = segmenter.segment_utf16(&utf16).collect();
assert_eq!(breaks, [0, 4], "Thai test");
}
#[test]
#[cfg(feature = "lstm")]
fn burmese_line_break() {
// "Burmese Language" in Burmese
const TEST_STR: &str = "မြန်မာဘာသာစကား";
let segmenter = LineSegmenter::new_lstm();
let breaks: Vec<usize> = segmenter.segment_str(TEST_STR).collect();
// LSTM model breaks more characters, but it is better to return [30].
assert_eq!(breaks, [0, 12, 18, 30, TEST_STR.len()], "Burmese test");
let utf16: Vec<u16> = TEST_STR.encode_utf16().collect();
let breaks: Vec<usize> = segmenter.segment_utf16(&utf16).collect();
// LSTM model breaks more characters, but it is better to return [10].
assert_eq!(breaks, [0, 4, 6, 10, utf16.len()], "Burmese utf-16 test");
}
#[test]
#[cfg(feature = "lstm")]
fn khmer_line_break() {
const TEST_STR: &str = "សេចក្ដីប្រកាសជាសកលស្ដីពីសិទ្ធិមនុស្ស";
let segmenter = LineSegmenter::new_lstm();
let breaks: Vec<usize> = segmenter.segment_str(TEST_STR).collect();
// Note: This small sample matches the ICU dictionary segmenter
assert_eq!(breaks, [0, 39, 48, 54, 72, TEST_STR.len()], "Khmer test");
let utf16: Vec<u16> = TEST_STR.encode_utf16().collect();
let breaks: Vec<usize> = segmenter.segment_utf16(&utf16).collect();
assert_eq!(
breaks,
[0, 13, 16, 18, 24, utf16.len()],
"Khmer utf-16 test"
);
}
#[test]
#[cfg(feature = "lstm")]
fn lao_line_break() {
const TEST_STR: &str = "ກ່ຽວກັບສິດຂອງມະນຸດ";
let segmenter = LineSegmenter::new_lstm();
let breaks: Vec<usize> = segmenter.segment_str(TEST_STR).collect();
// Note: LSTM finds a break at '12' that the dictionary does not find
assert_eq!(breaks, [0, 12, 21, 30, 39, TEST_STR.len()], "Lao test");
let utf16: Vec<u16> = TEST_STR.encode_utf16().collect();
let breaks: Vec<usize> = segmenter.segment_utf16(&utf16).collect();
assert_eq!(breaks, [0, 4, 7, 10, 13, utf16.len()], "Lao utf-16 test");
}
#[test]
fn empty_string() {
let segmenter = LineSegmenter::new_auto();
let breaks: Vec<usize> = segmenter.segment_str("").collect();
assert_eq!(breaks, [0]);
}
}