1797 lines
69 KiB
Rust
1797 lines
69 KiB
Rust
/*
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* meli - text_processing crate.
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*
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* Copyright 2017-2020 Manos Pitsidianakis
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*
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* This file is part of meli.
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*
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* meli is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* meli is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with meli. If not, see <http://www.gnu.org/licenses/>.
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*/
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extern crate unicode_segmentation;
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use self::unicode_segmentation::UnicodeSegmentation;
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use super::grapheme_clusters::TextProcessing;
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use super::tables::LINE_BREAK_RULES;
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use super::types::LineBreakClass;
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use super::types::Reflow;
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use core::cmp::Ordering;
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use core::iter::Peekable;
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use core::str::FromStr;
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use std::collections::VecDeque;
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use LineBreakClass::*;
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#[derive(Debug, PartialEq, Copy, Clone)]
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pub enum LineBreakCandidate {
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MandatoryBreak,
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BreakAllowed,
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NoBreak, // Not used.
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}
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impl Default for LineBreakCandidate {
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fn default() -> Self {
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LineBreakCandidate::NoBreak
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}
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}
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use LineBreakCandidate::*;
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pub struct LineBreakCandidateIter<'a> {
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text: &'a str,
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iter: Peekable<unicode_segmentation::GraphemeIndices<'a>>,
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pos: usize,
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/* Needed for rule LB30a */
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reg_ind_streak: u32,
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/* Needed for break before and after opportunities */
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break_now: bool,
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last_break: usize,
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}
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impl<'a> LineBreakCandidateIter<'a> {
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pub fn new(text: &'a str) -> Self {
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LineBreakCandidateIter {
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text,
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pos: 0,
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iter: UnicodeSegmentation::grapheme_indices(text, true).peekable(),
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reg_ind_streak: 0,
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break_now: false,
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last_break: 0,
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}
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}
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}
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macro_rules! get_base_character {
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($grapheme:ident) => {{
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char::from_str($grapheme.get(0..1).unwrap_or_else(|| {
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$grapheme.get(0..2).unwrap_or_else(|| {
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$grapheme
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.get(0..3)
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.unwrap_or_else(|| $grapheme.get(0..4).unwrap())
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})
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}))
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}};
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($grapheme:expr) => {{
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char::from_str($grapheme.get(0..1).unwrap_or_else(|| {
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$grapheme.get(0..2).unwrap_or_else(|| {
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$grapheme
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.get(0..3)
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.unwrap_or_else(|| $grapheme.get(0..4).unwrap())
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})
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}))
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}};
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}
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/// Side effects: none
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macro_rules! get_class {
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($grapheme:ident) => {{
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get_base_character!($grapheme)
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.map(|char| search_table(char as u32, LINE_BREAK_RULES))
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.unwrap_or(XX)
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}};
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($grapheme:expr) => {{
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get_base_character!($grapheme)
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.map(|char| search_table(char as u32, LINE_BREAK_RULES))
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.unwrap_or(XX)
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}};
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}
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/// Side effects: Updates $graph_iter and potentially $idx and $grapheme
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macro_rules! next_grapheme_class {
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($graph_iter:ident, $grapheme:ident) => ({
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if let Some((_, g)) = $graph_iter.next() {
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$grapheme = g;
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Some(get_class!(g))
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} else { None }
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});
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(($next_char:ident is $class:expr)) => ({
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$next_char.is_some() && get_class!(($next_char.unwrap().1)) == $class
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});
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(($next_char:ident is $($class:ident),+)) => ({
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$next_char.is_some() && ($(get_class!(($next_char.unwrap().1)) == $class)||+)
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});
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}
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trait EvenAfterSpaces {
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fn even_after_spaces(&self) -> &Self;
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}
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impl EvenAfterSpaces for str {
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fn even_after_spaces(&self) -> &Self {
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let mut ret = self;
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while !ret.is_empty() && get_class!(ret) != SP {
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ret = &ret[get_base_character!(ret).unwrap().len_utf8()..];
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}
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ret
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}
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}
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/// Returns positions where breaks can happen
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/// Examples:
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/// ```
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/// use melib::text_processing::{self, LineBreakCandidate::{self, *}};
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/// use melib::text_processing::line_break::LineBreakCandidateIter;
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///
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/// assert!(LineBreakCandidateIter::new("").collect::<Vec<(usize, LineBreakCandidate)>>().is_empty());
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/// assert_eq!(&[(7, BreakAllowed), (12, MandatoryBreak)],
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/// LineBreakCandidateIter::new("Sample Text.").collect::<Vec<(usize, LineBreakCandidate)>>().as_slice());
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/// assert_eq!(&[(3, MandatoryBreak), (7, MandatoryBreak), (10, BreakAllowed), (17, MandatoryBreak)],
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/// LineBreakCandidateIter::new("Sa\nmp\r\nle T(e)xt.").collect::<Vec<(usize, LineBreakCandidate)>>().as_slice());
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/// ```
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impl<'a> Iterator for LineBreakCandidateIter<'a> {
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type Item = (usize, LineBreakCandidate);
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fn next(&mut self) -> Option<Self::Item> {
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loop {
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macro_rules! set_last_break {
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($last_break:expr, $pos:expr) => {
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if $last_break == $pos {
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continue;
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}
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$last_break = $pos;
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};
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}
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// After end of text, there are no breaks.
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if self.pos > self.text.len() {
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return None;
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}
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// LB3 Always break at the end of text
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if self.pos == self.text.len() {
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let ret = self.pos;
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self.pos += 1;
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set_last_break!(self.last_break, ret);
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return Some((ret, MandatoryBreak));
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}
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let LineBreakCandidateIter {
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ref mut iter,
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text,
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ref mut reg_ind_streak,
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ref mut break_now,
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ref mut last_break,
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ref mut pos,
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} = self;
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let (idx, mut grapheme) = iter.next().unwrap();
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let iter = iter.by_ref();
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debug_assert_eq!(idx, *pos);
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let class = get_class!(grapheme);
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if class != RI {
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*reg_ind_streak = 0;
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}
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/* LB1 Assign a line breaking class to each code point of the input. Resolve AI, CB, CJ,
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* SA, SG, and XX into other line breaking classes depending on criteria outside the scope
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* of this algorithm.
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*
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* In the absence of such criteria all characters with a specific combination of original
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* class and General_Category property value are resolved as follows:
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* Resolved Original General_Category
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* AL AI, SG, XX Any
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* CM SA Only Mn or Mc
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* AL SA Any except Mn and Mc
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* NS SJ Any
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*/
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// TODO: LB1
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/* Check if next character class allows breaks before it */
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let mut next_char: Option<&(usize, &str)> = iter.peek();
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match class {
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BK => {
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// LB4 Always Break after hard line breaks.
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*pos += grapheme.len();
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set_last_break!(*last_break, *pos);
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return Some((*pos, MandatoryBreak));
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}
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// LB5 Treat CR followed by LF, as well as CR, LF, and NL as hard line breaks
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CR if next_grapheme_class!((next_char is LF)) => {
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*pos += grapheme.len();
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assert!(Some(LF) == next_grapheme_class!(iter, grapheme));
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*pos += grapheme.len();
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set_last_break!(*last_break, *pos);
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return Some((*pos, MandatoryBreak));
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}
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CR | LF | NL => {
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*pos += grapheme.len();
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set_last_break!(*last_break, *pos);
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return Some((*pos, MandatoryBreak));
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}
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_ => {}
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}
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if let Some((_, next_grapheme)) = next_char {
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let next_class = get_class!(next_grapheme);
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match next_class {
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/* LB6 Do not break before hard line breaks. × ( BK | CR | LF | NL ) */
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BK | CR | LF | NL => {
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*pos += grapheme.len();
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continue;
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}
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/* LB7 Do not break before spaces or zero width
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* space. × SP × ZW */
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SP | ZW => {
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*pos += grapheme.len();
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continue;
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}
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WJ => {
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/*: LB11 Do not break before or after Word joiner and related characters.*/
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*pos += grapheme.len();
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continue;
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}
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_ if *break_now => {
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*break_now = false;
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let ret = *pos;
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*pos += grapheme.len();
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// LB2 Never break at the start of text
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if ret == 0 {
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continue;
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}
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set_last_break!(*last_break, ret);
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return Some((ret, BreakAllowed));
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}
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_ => {}
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}
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}
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match class {
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ZW => {
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// LB8 Break before any character following a zero-width space, even if one or more
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// spaces intervene
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// ZW SP* ÷
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*pos += grapheme.len();
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while next_grapheme_class!((next_char is SP)) {
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let (_idx, grapheme) = iter.next().unwrap();
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debug_assert_eq!(get_class!(grapheme), SP);
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*pos += grapheme.len();
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next_char = iter.peek();
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}
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set_last_break!(*last_break, *pos);
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return Some((*pos, MandatoryBreak));
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}
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ZWJ => {
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// LB8a Do not break after a zero width joiner.
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*pos += grapheme.len();
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continue;
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}
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CM => {
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// LB9 Do not break a combining character sequence; treat it as if it has the line
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// breaking class of the base character in all of the following rules. Treat ZWJ as
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// if it were CM.
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// Treat X (CM | ZWJ)* as if it were X.
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// where X is any line break class except BK, CR, LF, NL, SP, or ZW.
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*pos += grapheme.len();
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continue;
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}
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WJ => {
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/*: LB11 Do not break before or after Word joiner and related characters.*/
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*pos += grapheme.len();
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/* Get next grapheme */
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if next_grapheme_class!(iter, grapheme).is_some() {
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*pos += grapheme.len();
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}
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continue;
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}
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GL => {
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/*LB12 Non-breaking characters: LB12 Do not break after NBSP and related characters.*/
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*pos += grapheme.len();
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continue;
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}
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_ => {}
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}
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if let Some((next_idx, next_grapheme)) = next_char {
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let next_class = get_class!(next_grapheme);
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match next_class {
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GL if ![SP, BA, HY].contains(&class) => {
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/* LB12a Do not break before NBSP and related characters, except after spaces and
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* hyphens. [^SP BA HY] × GL
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* Also LB12 Do not break after NBSP and related characters */
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*pos += grapheme.len();
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continue;
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}
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/* LB13 Do not break before ‘]’ or ‘!’ or ‘;’ or ‘/’, even after spaces. */
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CL | CP | EX | IS | SY => {
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*pos = *next_idx;
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continue;
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}
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_ => {}
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}
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}
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match class {
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/* LB13 Do not break before ‘]’ or ‘!’ or ‘;’ or ‘/’, even after spaces. */
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SP if !text[idx..].even_after_spaces().is_empty()
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&& [CL, CP, EX, IS, SY]
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.contains(&get_class!(text[idx..].even_after_spaces())) =>
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{
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*pos += grapheme.len();
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while ![CL, CP, EX, IS, SY]
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.contains(&next_grapheme_class!(iter, grapheme).unwrap())
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{
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*pos += grapheme.len();
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}
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*pos += grapheme.len();
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continue;
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}
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OP => {
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/* LB14 Do not break after ‘[’, even after spaces.
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* OP SP* ×
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*/
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*pos += grapheme.len();
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while next_grapheme_class!((next_char is SP)) {
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let (_idx, grapheme) = iter.next().unwrap();
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debug_assert_eq!(get_class!(grapheme), SP);
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*pos += grapheme.len();
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next_char = iter.peek();
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}
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continue;
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}
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QU if !text[idx + grapheme.len()..].even_after_spaces().is_empty()
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&& get_class!(text[idx + grapheme.len()..].even_after_spaces()) == OP =>
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{
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/* LB15 Do not break within ‘”[’, even with intervening spaces.
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* QU SP* × OP */
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*pos += grapheme.len();
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while next_grapheme_class!((next_char is SP)) {
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let (_idx, grapheme) = iter.next().unwrap();
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debug_assert_eq!(get_class!(grapheme), SP);
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*pos += grapheme.len();
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next_char = iter.peek();
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}
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continue;
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}
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QU => {
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/* LB19 Do not break before or after quotation marks, such as ‘ ” ’. */
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*pos += grapheme.len();
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if let Some((_, g)) = self.iter.next() {
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*pos += g.len();
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}
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continue;
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}
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CL | CP
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if !text[idx + grapheme.len()..].even_after_spaces().is_empty()
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&& get_class!(text[idx + grapheme.len()..].even_after_spaces()) == NS =>
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{
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/* LB16 Do not break between closing punctuation and a nonstarter (lb=NS), even with
|
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* intervening spaces.
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* (CL | CP) SP* × NS */
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*pos += grapheme.len();
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while Some(SP) == next_grapheme_class!(iter, grapheme) {
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*pos += grapheme.len();
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}
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continue;
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}
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B2 if !text[idx + grapheme.len()..].even_after_spaces().is_empty()
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&& get_class!(text[idx + grapheme.len()..].even_after_spaces()) == B2 =>
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{
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/* LB17 Do not break within ‘——’, even with intervening spaces.
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* B2 SP* × B2*/
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*pos += grapheme.len();
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continue;
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}
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SP => {
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/* LB18 Break after spaces. SP ÷ */
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*pos += grapheme.len();
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set_last_break!(*last_break, *pos);
|
||
return Some((*pos, BreakAllowed));
|
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}
|
||
_ => {}
|
||
}
|
||
if let Some((next_idx, next_grapheme)) = next_char {
|
||
let next_class = get_class!(next_grapheme);
|
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match next_class {
|
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QU if class != SP => {
|
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/* LB19 Do not break before or after quotation marks, such as ‘ ” ’. */
|
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*pos = *next_idx + next_grapheme.len();
|
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self.iter.next();
|
||
continue;
|
||
}
|
||
_ => {}
|
||
}
|
||
}
|
||
match class {
|
||
CB => {
|
||
/* LB20 Break before and after unresolved CB. */
|
||
let ret = *pos;
|
||
*pos += grapheme.len();
|
||
*break_now = true;
|
||
// LB2 Never break at the start of text
|
||
if ret == 0 {
|
||
continue;
|
||
}
|
||
set_last_break!(*last_break, ret);
|
||
return Some((ret, BreakAllowed));
|
||
}
|
||
/* LB21 Do not break before hyphen-minus, other hyphens, fixed-width spaces, small
|
||
* kana, and other non-starters, or after acute accents. × BA, × HY, × NS, BB × */
|
||
BB if !*break_now => {
|
||
*pos += grapheme.len();
|
||
continue;
|
||
}
|
||
_ => {}
|
||
}
|
||
|
||
if let Some((_, next_grapheme)) = next_char {
|
||
let next_class = get_class!(next_grapheme);
|
||
match next_class {
|
||
BA | HY | NS => {
|
||
/* LB21 Do not break before hyphen-minus, other hyphens, fixed-width spaces, small
|
||
* kana, and other non-starters, or after acute accents. × BA, × HY, × NS, BB × */
|
||
*pos += grapheme.len();
|
||
//*pos += next_grapheme.len();
|
||
continue;
|
||
}
|
||
_ => {}
|
||
}
|
||
}
|
||
match class {
|
||
HL if next_grapheme_class!((next_char is HY, BA)) => {
|
||
/* LB21a Don’t break after Hebrew + Hyphen. HL (HY | BA) × */
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB21b Don’t break between ,Solidus and Hebrew letters. SY × HL */
|
||
SY if next_grapheme_class!((next_char is HL)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
/* bypass next_char */
|
||
self.iter.next().unwrap();
|
||
if let Some((idx, next_grapheme)) = self.iter.next() {
|
||
*pos = idx + next_grapheme.len();
|
||
}
|
||
continue;
|
||
}
|
||
/* LB22 Do not break between two ellipses, or between letters, numbers or excla-
|
||
* mations and ellipsis.
|
||
* Examples: ‘9...’, ‘a...’, ‘H...’
|
||
* (AL | HL) × IN */
|
||
AL | HL if next_grapheme_class!((next_char is IN)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* EX × IN */
|
||
EX if next_grapheme_class!((next_char is IN)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
EX => {
|
||
// LB13
|
||
*pos += grapheme.len();
|
||
continue;
|
||
}
|
||
/* (ID | EB | EM) × IN */
|
||
ID | EB | EM if next_grapheme_class!((next_char is IN)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* IN × IN */
|
||
IN if next_grapheme_class!((next_char is IN)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* NU × IN */
|
||
NU if next_grapheme_class!((next_char is IN)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB23 Do not break between digits and letters.
|
||
* (AL | HL) × NU */
|
||
AL | HL if next_grapheme_class!((next_char is NU)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* NU × (AL | HL) */
|
||
NU if next_grapheme_class!((next_char is AL, HL)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB23a Do not break between numeric prefixes and ideographs, or between ideographs
|
||
* and numeric postfixes.
|
||
* PR × (ID | EB | EM) */
|
||
PR if next_grapheme_class!((next_char is ID, EB, EM)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* (ID | EB | EM) × PO */
|
||
ID | EB | EM if next_grapheme_class!((next_char is PO)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* B24 Do not break between numeric prefix/postfix and letters, or between
|
||
letters and prefix/postfix.
|
||
(PR | PO) × (AL | HL)*/
|
||
PR | PO if next_grapheme_class!((next_char is AL, HL)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/*(AL | HL) × (PR | PO) */
|
||
AL | HL if next_grapheme_class!((next_char is PR, PO)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB25 Do not break between the following pairs of classes relevant to numbers:
|
||
* CL × PO */
|
||
CL if next_grapheme_class!((next_char is PO)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* CP × PO */
|
||
CP if next_grapheme_class!((next_char is PO)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* CL × PR */
|
||
CL if next_grapheme_class!((next_char is PR)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* CP × PR */
|
||
CP if next_grapheme_class!((next_char is PR)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* NU × PO */
|
||
NU if next_grapheme_class!((next_char is PO)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* NU × PR */
|
||
NU if next_grapheme_class!((next_char is PR)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* PO × OP */
|
||
PO if next_grapheme_class!((next_char is OP)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* PO × NU */
|
||
PO if next_grapheme_class!((next_char is NU)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* PR × OP */
|
||
PR if next_grapheme_class!((next_char is OP)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* PR × NU */
|
||
PR if next_grapheme_class!((next_char is NU)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* HY × NU */
|
||
HY if next_grapheme_class!((next_char is NU)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* IS × NU */
|
||
IS if next_grapheme_class!((next_char is NU)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* NU × NU */
|
||
NU if next_grapheme_class!((next_char is NU)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* SY × NU */
|
||
SY if next_grapheme_class!((next_char is NU)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB26 Do not break a Korean syllable.
|
||
* JL × (JL | JV | H2 | H3) */
|
||
JL if next_grapheme_class!((next_char is JL, JV, H2, H3)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* (JV | H2) × (JV | JT) */
|
||
JV | H2 if next_grapheme_class!((next_char is JV, JT)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* (JT | H3) × JT */
|
||
JT | H3 if next_grapheme_class!((next_char is JT)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB27 Treat a Korean Syllable Block the same as ID.
|
||
* (JL | JV | JT | H2 | H3) × IN */
|
||
JL | JV | JT | H2 | H3 if next_grapheme_class!((next_char is IN)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* (JL | JV | JT | H2 | H3) × PO */
|
||
JL | JV | JT | H2 | H3 if next_grapheme_class!((next_char is PO)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* PR × (JL | JV | JT | H2 | H3) */
|
||
PR if next_grapheme_class!((next_char is JL, JV, JT, H2, H3)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB28 Do not break between alphabetics (“at”).
|
||
(AL | HL) × (AL | HL) */
|
||
AL | HL if next_grapheme_class!((next_char is AL, HL)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB29 Do not break between numeric punctuation and alphabetics (“e.g.”).
|
||
IS × (AL | HL) */
|
||
IS if next_grapheme_class!((next_char is AL, HL)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* LB30 Do not break between letters, numbers, or ordinary symbols and opening
|
||
or closing parentheses.
|
||
(AL | HL | NU) × OP */
|
||
AL | HL | NU if next_grapheme_class!((next_char is OP)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/* CP × (AL | HL | NU) */
|
||
CP if next_grapheme_class!((next_char is AL, HL , NU)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
/*LB30b Do not break between an emoji base and an emoji modifier.
|
||
* EB × EM */
|
||
EB if next_grapheme_class!((next_char is EM)) => {
|
||
let (idx, next_grapheme) = next_char.unwrap();
|
||
*pos = idx + next_grapheme.len();
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
RI => {
|
||
/* LB30a Break between two regional indicator symbols if and only if there are an
|
||
* even number of regional indicators preceding the position of the break.
|
||
* sot (RI RI)* RI × RI
|
||
* [^RI] (RI RI)* RI × RI */
|
||
*reg_ind_streak += 1;
|
||
*pos += grapheme.len();
|
||
if *reg_ind_streak % 2 == 1 {
|
||
let ret = *pos - grapheme.len();
|
||
// LB2 Never break at the start of text
|
||
if ret == 0 {
|
||
continue;
|
||
}
|
||
set_last_break!(*last_break, ret);
|
||
return Some((ret, BreakAllowed));
|
||
}
|
||
self.iter.next();
|
||
continue;
|
||
}
|
||
CL | CP | IS | SY => {
|
||
*pos += grapheme.len();
|
||
continue;
|
||
}
|
||
BK | CR | LF | NL => {
|
||
*pos += grapheme.len();
|
||
continue;
|
||
}
|
||
SP | ZW => {
|
||
*pos += grapheme.len();
|
||
continue;
|
||
}
|
||
BA | HY | NS => {
|
||
*pos += grapheme.len();
|
||
continue;
|
||
}
|
||
_ => {
|
||
/* LB31 Break everywhere else.
|
||
* ALL ÷
|
||
* ÷ ALL
|
||
*/
|
||
let ret = *pos;
|
||
// ALL ÷
|
||
*break_now = true;
|
||
*pos += grapheme.len();
|
||
// LB2 Never break at the start of text
|
||
if ret == 0 {
|
||
continue;
|
||
}
|
||
// ÷ ALL
|
||
set_last_break!(*last_break, ret);
|
||
return Some((ret, BreakAllowed));
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
fn search_table(c: u32, t: &'static [(u32, u32, LineBreakClass)]) -> LineBreakClass {
|
||
match t.binary_search_by(|&(lo, hi, _)| {
|
||
if lo <= c && c <= hi {
|
||
Ordering::Equal
|
||
} else if hi < c {
|
||
Ordering::Less
|
||
} else {
|
||
Ordering::Greater
|
||
}
|
||
}) {
|
||
Ok(idx) => t[idx].2,
|
||
Err(_) => XX,
|
||
}
|
||
}
|
||
|
||
#[cfg(test)]
|
||
mod tests {
|
||
use super::*;
|
||
|
||
#[test]
|
||
fn test_line_breaks() {
|
||
let s = "Fell past it.\n\n‘Well!’ thought Alice to herself.";
|
||
let breaks = LineBreakCandidateIter::new(s).collect::<Vec<(usize, LineBreakCandidate)>>();
|
||
let mut prev = 0;
|
||
for b in breaks {
|
||
println!("{:?}", &s[prev..b.0]);
|
||
prev = b.0;
|
||
}
|
||
println!("{:?}", &s[prev..]);
|
||
|
||
let s = r#"Τ' άστρα τα κοντά -στη γλυκιά σελήνη
|
||
την ειδή των κρύβουν - τη διαμαντένια,
|
||
άμα φως λαμπρό -στη γή πάσα χύνει,
|
||
όλη ασημένια."#;
|
||
let breaks = LineBreakCandidateIter::new(s).collect::<Vec<(usize, LineBreakCandidate)>>();
|
||
let mut prev = 0;
|
||
for b in breaks {
|
||
println!("{:?}", &s[prev..b.0]);
|
||
prev = b.0;
|
||
}
|
||
println!("{:?}", &s[prev..]);
|
||
}
|
||
}
|
||
|
||
pub use alg::linear;
|
||
|
||
mod alg {
|
||
use super::super::grapheme_clusters::TextProcessing;
|
||
use super::super::*;
|
||
fn cost(i: usize, j: usize, width: usize, minima: &[usize], offsets: &[usize]) -> usize {
|
||
let w = offsets[j] + j - offsets[i] - i - 1;
|
||
if w > width {
|
||
return 65536 * (w - width);
|
||
}
|
||
minima[i] + (width - w) * (width - w)
|
||
}
|
||
|
||
fn smawk(
|
||
rows: &mut Vec<usize>,
|
||
columns: &mut Vec<usize>,
|
||
minima: &mut Vec<usize>,
|
||
breaks: &mut Vec<usize>,
|
||
width: usize,
|
||
offsets: &[usize],
|
||
) {
|
||
let mut stack = Vec::new();
|
||
let mut i = 0;
|
||
while i < rows.len() {
|
||
if !stack.is_empty() {
|
||
let c = columns[stack.len() - 1];
|
||
if cost(*stack.iter().last().unwrap(), c, width, minima, offsets)
|
||
< cost(rows[i], c, width, minima, offsets)
|
||
{
|
||
if stack.len() < columns.len() {
|
||
stack.push(rows[i]);
|
||
}
|
||
i += 1;
|
||
} else {
|
||
stack.pop();
|
||
}
|
||
} else {
|
||
stack.push(rows[i]);
|
||
i += 1;
|
||
}
|
||
}
|
||
let rows = &mut stack;
|
||
if columns.len() > 1 {
|
||
let mut odd_columns = columns.iter().skip(1).step_by(2).cloned().collect();
|
||
smawk(rows, &mut odd_columns, minima, breaks, width, offsets);
|
||
for (i, o) in odd_columns.into_iter().enumerate() {
|
||
columns[2 * i + 1] = o;
|
||
}
|
||
}
|
||
let mut i = 0;
|
||
let mut j = 0;
|
||
while j < columns.len() {
|
||
let end = if j + 1 < columns.len() {
|
||
breaks[columns[j + 1]]
|
||
} else {
|
||
*rows.iter().last().unwrap()
|
||
};
|
||
let c = cost(rows[i], columns[j], width, minima, offsets);
|
||
if c < minima[columns[j]] {
|
||
minima[columns[j]] = c;
|
||
breaks[columns[j]] = rows[i];
|
||
}
|
||
if rows[i] < end {
|
||
i += 1;
|
||
} else {
|
||
j += 2;
|
||
}
|
||
}
|
||
}
|
||
|
||
pub fn linear(text: &str, width: usize) -> Vec<String> {
|
||
let mut words = Vec::new();
|
||
let breaks =
|
||
LineBreakCandidateIter::new(text).collect::<Vec<(usize, LineBreakCandidate)>>();
|
||
{
|
||
let mut prev = 0;
|
||
for b in breaks {
|
||
if text[prev..b.0].ends_with('\n') && text[b.0..].starts_with('\n') {
|
||
words.push(text[prev..b.0].trim_end_matches('\n'));
|
||
words.push("\n\n");
|
||
} else if &text[prev..b.0] != "\n" {
|
||
words.push(text[prev..b.0].trim_end_matches('\n'));
|
||
if text[prev..b.0].ends_with('\n') {
|
||
words.push(" ");
|
||
}
|
||
}
|
||
prev = b.0;
|
||
}
|
||
if &text[prev..] != "\n" {
|
||
words.push(text[prev..].trim_end_matches('\n'));
|
||
}
|
||
}
|
||
let count = words.len();
|
||
let mut minima = vec![std::usize::MAX - 1; count + 1];
|
||
minima[0] = 0;
|
||
let mut offsets = Vec::with_capacity(words.len());
|
||
offsets.push(0);
|
||
for w in words.iter() {
|
||
if *w == "\n\n" {
|
||
offsets.push(offsets.iter().last().unwrap() + width - 1);
|
||
} else {
|
||
offsets.push(offsets.iter().last().unwrap() + w.grapheme_len().saturating_sub(1));
|
||
}
|
||
}
|
||
|
||
let mut breaks = vec![0; count + 1];
|
||
|
||
let mut n = count + 1;
|
||
let mut i = 1;
|
||
let mut offset = 0;
|
||
loop {
|
||
let r = std::cmp::min(n, 2 * i);
|
||
let edge = i + offset;
|
||
smawk(
|
||
&mut (offset..edge).collect(),
|
||
&mut (edge..(r + offset)).collect(),
|
||
&mut minima,
|
||
&mut breaks,
|
||
width,
|
||
&offsets,
|
||
);
|
||
let x = minima[r - 1 + offset];
|
||
let mut for_was_broken = false;
|
||
for j in i..(r - 1) {
|
||
let y = cost(j + offset, r - 1 + offset, width, &minima, &offsets);
|
||
if y <= x {
|
||
n -= j;
|
||
i = 1;
|
||
offset += j;
|
||
for_was_broken = true;
|
||
break;
|
||
}
|
||
}
|
||
|
||
if !for_was_broken {
|
||
if r == n {
|
||
break;
|
||
}
|
||
i *= 2;
|
||
}
|
||
}
|
||
let paragraphs = text.split("\n\n").count();
|
||
let mut lines = Vec::new();
|
||
let mut j = count;
|
||
let mut p_i = 0;
|
||
while j > 0 {
|
||
let mut line = String::new();
|
||
for word in words.iter().take(j).skip(breaks[j]) {
|
||
line.push_str(word);
|
||
}
|
||
lines.push(line);
|
||
if p_i + 1 < paragraphs {
|
||
lines.push(String::new());
|
||
p_i += 1;
|
||
}
|
||
j = breaks[j];
|
||
}
|
||
lines.reverse();
|
||
lines
|
||
}
|
||
}
|
||
|
||
pub fn split_lines_reflow(text: &str, reflow: Reflow, width: Option<usize>) -> Vec<String> {
|
||
match reflow {
|
||
Reflow::FormatFlowed => {
|
||
/* rfc3676 - The Text/Plain Format and DelSp Parameters
|
||
* https://tools.ietf.org/html/rfc3676 */
|
||
|
||
let mut ret = Vec::new();
|
||
/*
|
||
* - Split lines with indices using str::match_indices()
|
||
* - Iterate and reflow flow regions, and pass fixed regions through
|
||
*/
|
||
let lines_indices: Vec<usize> = text.match_indices('\n').map(|(i, _)| i).collect();
|
||
let mut prev_index = 0;
|
||
let mut in_paragraph = false;
|
||
let mut paragraph_start = 0;
|
||
|
||
let mut prev_quote_depth = 0;
|
||
for i in &lines_indices {
|
||
let line = &text[prev_index..*i];
|
||
let mut trimmed = line.trim_start().lines().next().unwrap_or("");
|
||
let mut quote_depth = 0;
|
||
let p_str: usize = trimmed
|
||
.as_bytes()
|
||
.iter()
|
||
.position(|&b| {
|
||
if b != b'>' {
|
||
/* position() is short-circuiting */
|
||
true
|
||
} else {
|
||
quote_depth += 1;
|
||
false
|
||
}
|
||
})
|
||
.unwrap_or(0);
|
||
trimmed = &trimmed[p_str..];
|
||
if trimmed.starts_with(' ') {
|
||
/* Remove space stuffing before checking for ending space character.
|
||
* [rfc3676#section-4.4] */
|
||
trimmed = &trimmed[1..];
|
||
}
|
||
|
||
if trimmed.ends_with(' ') {
|
||
if !in_paragraph {
|
||
in_paragraph = true;
|
||
paragraph_start = prev_index;
|
||
} else if prev_quote_depth == quote_depth {
|
||
/* This becomes part of the paragraph we're in */
|
||
} else {
|
||
/*Malformed line, different quote depths can't be in the same paragraph. */
|
||
let paragraph = &text[paragraph_start..prev_index];
|
||
reflow_helper(&mut ret, paragraph, prev_quote_depth, in_paragraph, width);
|
||
|
||
paragraph_start = prev_index;
|
||
}
|
||
} else {
|
||
if prev_quote_depth == quote_depth || !in_paragraph {
|
||
let paragraph = &text[paragraph_start..*i];
|
||
reflow_helper(&mut ret, paragraph, quote_depth, in_paragraph, width);
|
||
} else {
|
||
/*Malformed line, different quote depths can't be in the same paragraph. */
|
||
let paragraph = &text[paragraph_start..prev_index];
|
||
reflow_helper(&mut ret, paragraph, prev_quote_depth, in_paragraph, width);
|
||
let paragraph = &text[prev_index..*i];
|
||
reflow_helper(&mut ret, paragraph, quote_depth, false, width);
|
||
}
|
||
paragraph_start = *i;
|
||
in_paragraph = false;
|
||
}
|
||
prev_quote_depth = quote_depth;
|
||
prev_index = *i;
|
||
}
|
||
let paragraph = &text[paragraph_start..text.len()];
|
||
reflow_helper(&mut ret, paragraph, prev_quote_depth, in_paragraph, width);
|
||
ret
|
||
}
|
||
Reflow::All => {
|
||
if let Some(width) = width {
|
||
let mut ret = Vec::new();
|
||
let width = width.saturating_sub(2);
|
||
|
||
for line in text.lines() {
|
||
if line.grapheme_len() <= width {
|
||
ret.push(line.to_string());
|
||
continue;
|
||
}
|
||
|
||
let breaks = LineBreakCandidateIter::new(line)
|
||
.collect::<Vec<(usize, LineBreakCandidate)>>();
|
||
if breaks.len() < 2 {
|
||
split(&mut ret, line, width);
|
||
continue;
|
||
}
|
||
let segment_tree = {
|
||
use std::iter::FromIterator;
|
||
let mut t: smallvec::SmallVec<[usize; 1024]> =
|
||
smallvec::SmallVec::from_iter(std::iter::repeat(0).take(line.len()));
|
||
for (idx, _g) in UnicodeSegmentation::grapheme_indices(line, true) {
|
||
t[idx] = 1;
|
||
}
|
||
Box::new(segment_tree::SegmentTree::new(t))
|
||
};
|
||
|
||
let mut prev = 0;
|
||
let mut prev_line_offset = 0;
|
||
while prev < breaks.len() {
|
||
let new_off = match breaks[prev..].binary_search_by(|(offset, _)| {
|
||
segment_tree
|
||
.get_sum(prev_line_offset, offset.saturating_sub(1))
|
||
.cmp(&width)
|
||
}) {
|
||
Ok(v) => v,
|
||
Err(v) => v,
|
||
} + prev;
|
||
let end_offset = if new_off >= breaks.len() {
|
||
line.len()
|
||
} else {
|
||
breaks[new_off].0
|
||
};
|
||
if !line[prev_line_offset..end_offset].is_empty() {
|
||
if prev_line_offset == 0 {
|
||
ret.push(line[prev_line_offset..end_offset].to_string());
|
||
} else {
|
||
ret.push(format!("⤷{}", &line[prev_line_offset..end_offset]));
|
||
}
|
||
}
|
||
if prev_line_offset == end_offset && prev == new_off {
|
||
break;
|
||
}
|
||
prev_line_offset = end_offset;
|
||
prev = new_off;
|
||
}
|
||
}
|
||
ret
|
||
} else {
|
||
text.trim().split('\n').map(str::to_string).collect()
|
||
}
|
||
}
|
||
Reflow::No => text.trim().split('\n').map(str::to_string).collect(),
|
||
}
|
||
}
|
||
|
||
fn split(ret: &mut Vec<String>, mut line: &str, width: usize) {
|
||
while !line.is_empty() {
|
||
let mut chop_index = std::cmp::min(line.len().saturating_sub(1), width);
|
||
while chop_index > 0 && !line.is_char_boundary(chop_index) {
|
||
chop_index -= 1;
|
||
}
|
||
if chop_index == 0 {
|
||
ret.push(format!("⤷{}", line));
|
||
return;
|
||
} else {
|
||
ret.push(format!("⤷{}", &line[..chop_index]));
|
||
}
|
||
line = &line[chop_index..];
|
||
}
|
||
}
|
||
fn reflow_helper(
|
||
ret: &mut Vec<String>,
|
||
paragraph: &str,
|
||
quote_depth: usize,
|
||
in_paragraph: bool,
|
||
width: Option<usize>,
|
||
) {
|
||
if quote_depth > 0 {
|
||
let quotes: String = ">".repeat(quote_depth);
|
||
let paragraph = paragraph
|
||
.trim_start_matches("es)
|
||
.replace(&format!("\n{}", "es), "")
|
||
.replace("\n", "")
|
||
.replace("\r", "");
|
||
if in_paragraph {
|
||
if let Some(width) = width {
|
||
ret.extend(
|
||
linear(¶graph, width.saturating_sub(quote_depth))
|
||
.into_iter()
|
||
.map(|l| format!("{}{}", "es, l)),
|
||
);
|
||
} else {
|
||
ret.push(format!("{}{}", "es, ¶graph));
|
||
}
|
||
} else {
|
||
ret.push(format!("{}{}", "es, ¶graph));
|
||
}
|
||
} else {
|
||
let paragraph = paragraph.replace("\n", "").replace("\r", "");
|
||
|
||
if in_paragraph {
|
||
if let Some(width) = width {
|
||
let ex = linear(¶graph, width);
|
||
ret.extend(ex.into_iter());
|
||
} else {
|
||
ret.push(paragraph);
|
||
}
|
||
} else {
|
||
ret.push(paragraph);
|
||
}
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn test_reflow() {
|
||
let text = r#"`Take some more tea,' the March Hare said to Alice, very
|
||
earnestly.
|
||
|
||
`I've had nothing yet,' Alice replied in an offended tone, `so
|
||
I can't take more.'
|
||
|
||
`You mean you can't take LESS,' said the Hatter: `it's very
|
||
easy to take MORE than nothing.'"#;
|
||
for l in split_lines_reflow(text, Reflow::FormatFlowed, Some(30)) {
|
||
println!("{}", l);
|
||
}
|
||
println!();
|
||
for l in split_lines_reflow(text, Reflow::No, Some(30)) {
|
||
println!("{}", l);
|
||
}
|
||
println!();
|
||
let text = r#">>>Take some more tea.
|
||
>>I've had nothing yet, so I can't take more.
|
||
>You mean you can't take LESS, it's very easy to take
|
||
>MORE than nothing."#;
|
||
for l in split_lines_reflow(text, Reflow::FormatFlowed, Some(20)) {
|
||
println!("{}", l);
|
||
}
|
||
println!();
|
||
for l in split_lines_reflow(text, Reflow::No, Some(20)) {
|
||
println!("{}", l);
|
||
}
|
||
println!();
|
||
use super::_ALICE_CHAPTER_1;
|
||
for l in split_lines_reflow(_ALICE_CHAPTER_1, Reflow::FormatFlowed, Some(72)) {
|
||
println!("{}", l);
|
||
}
|
||
}
|
||
|
||
mod segment_tree {
|
||
/*! Simple segment tree implementation for maximum in range queries. This is useful if given an
|
||
* array of numbers you want to get the maximum value inside an interval quickly.
|
||
*/
|
||
use smallvec::SmallVec;
|
||
use std::convert::TryFrom;
|
||
use std::iter::FromIterator;
|
||
|
||
#[derive(Default, Debug, Clone)]
|
||
pub(super) struct SegmentTree {
|
||
array: SmallVec<[usize; 1024]>,
|
||
tree: SmallVec<[usize; 1024]>,
|
||
}
|
||
|
||
impl SegmentTree {
|
||
pub(super) fn new(val: SmallVec<[usize; 1024]>) -> SegmentTree {
|
||
if val.is_empty() {
|
||
return SegmentTree {
|
||
array: val.clone(),
|
||
tree: val,
|
||
};
|
||
}
|
||
|
||
let height = (f64::from(u32::try_from(val.len()).unwrap_or(0)))
|
||
.log2()
|
||
.ceil() as u32;
|
||
let max_size = 2 * (2_usize.pow(height));
|
||
|
||
let mut segment_tree: SmallVec<[usize; 1024]> =
|
||
SmallVec::from_iter(core::iter::repeat(0).take(max_size));
|
||
for i in 0..val.len() {
|
||
segment_tree[val.len() + i] = val[i];
|
||
}
|
||
|
||
for i in (1..val.len()).rev() {
|
||
segment_tree[i] = segment_tree[2 * i] + segment_tree[2 * i + 1];
|
||
}
|
||
|
||
SegmentTree {
|
||
array: val,
|
||
tree: segment_tree,
|
||
}
|
||
}
|
||
|
||
/// (left, right) is inclusive
|
||
pub(super) fn get_sum(&self, mut left: usize, mut right: usize) -> usize {
|
||
if self.array.is_empty() {
|
||
return 0;
|
||
}
|
||
|
||
let len = self.array.len();
|
||
if left > right {
|
||
return 0;
|
||
}
|
||
if right >= len {
|
||
right = len.saturating_sub(1);
|
||
}
|
||
|
||
left += len;
|
||
right += len + 1;
|
||
|
||
let mut sum = 0;
|
||
|
||
while left < right {
|
||
if (left & 1) > 0 {
|
||
sum += self.tree[left];
|
||
left += 1;
|
||
}
|
||
|
||
if (right & 1) > 0 {
|
||
right -= 1;
|
||
sum += self.tree[right];
|
||
}
|
||
|
||
left /= 2;
|
||
right /= 2;
|
||
}
|
||
sum
|
||
}
|
||
}
|
||
}
|
||
|
||
/// A lazy stateful iterator for line breaking text. Useful for very long text where you don't want
|
||
/// to linebreak it completely before user requests specific lines.
|
||
#[derive(Debug, Clone)]
|
||
pub struct LineBreakText {
|
||
text: String,
|
||
reflow: Reflow,
|
||
paragraph: VecDeque<String>,
|
||
paragraph_start_index: usize,
|
||
width: Option<usize>,
|
||
state: ReflowState,
|
||
}
|
||
|
||
#[derive(Debug, Clone)]
|
||
enum ReflowState {
|
||
No {
|
||
cur_index: usize,
|
||
},
|
||
AllWidth {
|
||
width: usize,
|
||
state: LineBreakTextState,
|
||
},
|
||
All {
|
||
cur_index: usize,
|
||
},
|
||
FormatFlowed {
|
||
cur_index: usize,
|
||
},
|
||
}
|
||
|
||
impl ReflowState {
|
||
fn new(reflow: Reflow, width: Option<usize>, cur_index: usize) -> ReflowState {
|
||
match reflow {
|
||
Reflow::All if width.is_some() => ReflowState::AllWidth {
|
||
width: width.unwrap(),
|
||
state: LineBreakTextState::AtLine { cur_index },
|
||
},
|
||
Reflow::All => ReflowState::All { cur_index },
|
||
Reflow::FormatFlowed => ReflowState::FormatFlowed { cur_index },
|
||
Reflow::No => ReflowState::No { cur_index },
|
||
}
|
||
}
|
||
}
|
||
|
||
#[derive(Debug, Clone)]
|
||
enum LineBreakTextState {
|
||
AtLine {
|
||
cur_index: usize,
|
||
},
|
||
WithinLine {
|
||
line_index: usize,
|
||
line_length: usize,
|
||
within_line_index: usize,
|
||
breaks: Vec<(usize, LineBreakCandidate)>,
|
||
prev_break: usize,
|
||
segment_tree: Box<segment_tree::SegmentTree>,
|
||
},
|
||
}
|
||
|
||
impl Default for LineBreakText {
|
||
fn default() -> Self {
|
||
Self::new(String::new(), Reflow::default(), None)
|
||
}
|
||
}
|
||
|
||
impl LineBreakText {
|
||
pub fn new(text: String, reflow: Reflow, width: Option<usize>) -> Self {
|
||
LineBreakText {
|
||
text,
|
||
state: ReflowState::new(reflow, width, 0),
|
||
paragraph: VecDeque::new(),
|
||
paragraph_start_index: 0,
|
||
reflow,
|
||
width,
|
||
}
|
||
}
|
||
|
||
pub fn width(&self) -> Option<usize> {
|
||
self.width
|
||
}
|
||
|
||
pub fn set_reflow(&mut self, new_val: Reflow) -> &mut Self {
|
||
self.reflow = new_val;
|
||
self.paragraph.clear();
|
||
self.state = ReflowState::new(self.reflow, self.width, self.paragraph_start_index);
|
||
self
|
||
}
|
||
|
||
pub fn set_width(&mut self, new_val: Option<usize>) -> &mut Self {
|
||
self.width = new_val;
|
||
self.paragraph.clear();
|
||
self.state = ReflowState::new(self.reflow, self.width, self.paragraph_start_index);
|
||
self
|
||
}
|
||
|
||
pub fn set_text(&mut self, new_val: String) -> &mut Self {
|
||
self.text = new_val;
|
||
self.reset()
|
||
}
|
||
|
||
pub fn reset(&mut self) -> &mut Self {
|
||
self.paragraph.clear();
|
||
self.state = ReflowState::new(self.reflow, self.width, 0);
|
||
self.paragraph_start_index = 0;
|
||
self
|
||
}
|
||
|
||
pub fn is_finished(&self) -> bool {
|
||
match self.state {
|
||
ReflowState::No { cur_index }
|
||
| ReflowState::All { cur_index }
|
||
| ReflowState::FormatFlowed { cur_index }
|
||
| ReflowState::AllWidth {
|
||
width: _,
|
||
state: LineBreakTextState::AtLine { cur_index },
|
||
} => cur_index >= self.text.len(),
|
||
ReflowState::AllWidth {
|
||
width: _,
|
||
state: LineBreakTextState::WithinLine { .. },
|
||
} => false,
|
||
}
|
||
}
|
||
}
|
||
|
||
impl Iterator for LineBreakText {
|
||
type Item = String;
|
||
fn next(&mut self) -> Option<Self::Item> {
|
||
if !self.paragraph.is_empty() {
|
||
return self.paragraph.pop_front();
|
||
}
|
||
if self.is_finished() {
|
||
return None;
|
||
}
|
||
match self.state {
|
||
ReflowState::FormatFlowed { ref mut cur_index } => {
|
||
/* rfc3676 - The Text/Plain Format and DelSp Parameters
|
||
* https://tools.ietf.org/html/rfc3676 */
|
||
|
||
/*
|
||
* - Split lines with indices using str::match_indices()
|
||
* - Iterate and reflow flow regions, and pass fixed regions through
|
||
*/
|
||
self.paragraph_start_index = *cur_index;
|
||
let line_indices_iter = self.text[*cur_index..].match_indices('\n').map(|(i, _)| i);
|
||
let start_offset = *cur_index;
|
||
let mut prev_index = *cur_index;
|
||
let mut in_paragraph = false;
|
||
let mut paragraph_start = *cur_index;
|
||
|
||
let mut prev_quote_depth = 0;
|
||
let mut paragraph = VecDeque::new();
|
||
for i in line_indices_iter {
|
||
let i = i + start_offset + 1;
|
||
let line = &self.text[prev_index..i];
|
||
let mut trimmed = line.trim_start().lines().next().unwrap_or("");
|
||
let mut quote_depth = 0;
|
||
let p_str: usize = trimmed
|
||
.as_bytes()
|
||
.iter()
|
||
.position(|&b| {
|
||
if b != b'>' {
|
||
/* position() is short-circuiting */
|
||
true
|
||
} else {
|
||
quote_depth += 1;
|
||
false
|
||
}
|
||
})
|
||
.unwrap_or(0);
|
||
trimmed = &trimmed[p_str..];
|
||
if trimmed.starts_with(' ') {
|
||
/* Remove space stuffing before checking for ending space character.
|
||
* [rfc3676#section-4.4] */
|
||
trimmed = &trimmed[1..];
|
||
}
|
||
|
||
if trimmed.ends_with(' ') {
|
||
if !in_paragraph {
|
||
in_paragraph = true;
|
||
paragraph_start = prev_index;
|
||
} else if prev_quote_depth == quote_depth {
|
||
/* This becomes part of the paragraph we're in */
|
||
} else {
|
||
/*Malformed line, different quote depths can't be in the same paragraph. */
|
||
let paragraph_s = &self.text[paragraph_start..prev_index];
|
||
reflow_helper2(
|
||
&mut paragraph,
|
||
paragraph_s,
|
||
prev_quote_depth,
|
||
in_paragraph,
|
||
self.width,
|
||
);
|
||
|
||
paragraph_start = prev_index;
|
||
}
|
||
} else {
|
||
if prev_quote_depth == quote_depth || !in_paragraph {
|
||
let paragraph_s = &self.text[paragraph_start..i];
|
||
reflow_helper2(
|
||
&mut paragraph,
|
||
paragraph_s,
|
||
quote_depth,
|
||
in_paragraph,
|
||
self.width,
|
||
);
|
||
} else {
|
||
/*Malformed line, different quote depths can't be in the same paragraph. */
|
||
let paragraph_s = &self.text[paragraph_start..prev_index];
|
||
reflow_helper2(
|
||
&mut paragraph,
|
||
paragraph_s,
|
||
prev_quote_depth,
|
||
in_paragraph,
|
||
self.width,
|
||
);
|
||
let paragraph_s = &self.text[prev_index..i];
|
||
reflow_helper2(
|
||
&mut paragraph,
|
||
paragraph_s,
|
||
quote_depth,
|
||
false,
|
||
self.width,
|
||
);
|
||
}
|
||
*cur_index = i;
|
||
std::mem::swap(&mut self.paragraph, &mut paragraph);
|
||
paragraph_start = i;
|
||
in_paragraph = false;
|
||
break;
|
||
}
|
||
*cur_index = i;
|
||
prev_quote_depth = quote_depth;
|
||
prev_index = i;
|
||
}
|
||
if in_paragraph {
|
||
let paragraph_s = &self.text[paragraph_start..self.text.len()];
|
||
*cur_index = self.text.len();
|
||
reflow_helper2(
|
||
&mut paragraph,
|
||
paragraph_s,
|
||
prev_quote_depth,
|
||
in_paragraph,
|
||
self.width,
|
||
);
|
||
self.paragraph = paragraph;
|
||
}
|
||
return self.paragraph.pop_front();
|
||
}
|
||
ReflowState::AllWidth {
|
||
width,
|
||
ref mut state,
|
||
} => {
|
||
let width = width.saturating_sub(2);
|
||
|
||
loop {
|
||
let line: &str;
|
||
let cur_index: &mut usize;
|
||
let within_line_index: &mut usize;
|
||
let prev_break: &mut usize;
|
||
let segment_tree: &segment_tree::SegmentTree;
|
||
let breaks: &Vec<(usize, LineBreakCandidate)>;
|
||
match state {
|
||
LineBreakTextState::AtLine {
|
||
cur_index: ref mut _cur_index,
|
||
} => {
|
||
line = if let Some(line) = self
|
||
.text
|
||
.get(*_cur_index..)
|
||
.and_then(|slice| slice.split('\n').next())
|
||
{
|
||
line
|
||
} else {
|
||
*_cur_index = self.text.len();
|
||
return None;
|
||
};
|
||
let _cur_index = *_cur_index;
|
||
*state = LineBreakTextState::WithinLine {
|
||
line_index: _cur_index,
|
||
line_length: line.len(),
|
||
within_line_index: 0,
|
||
breaks: LineBreakCandidateIter::new(line).collect::<Vec<(
|
||
usize,
|
||
LineBreakCandidate,
|
||
)>>(
|
||
),
|
||
prev_break: 0,
|
||
segment_tree: {
|
||
use std::iter::FromIterator;
|
||
let mut t: smallvec::SmallVec<[usize; 1024]> =
|
||
smallvec::SmallVec::from_iter(
|
||
std::iter::repeat(0).take(line.len()),
|
||
);
|
||
for (idx, _g) in
|
||
UnicodeSegmentation::grapheme_indices(line, true)
|
||
{
|
||
t[idx] = 1;
|
||
}
|
||
Box::new(segment_tree::SegmentTree::new(t))
|
||
},
|
||
};
|
||
if let LineBreakTextState::WithinLine {
|
||
ref mut line_index,
|
||
line_length: _,
|
||
within_line_index: ref mut _within_line_index,
|
||
breaks: ref _breaks,
|
||
prev_break: ref mut _prev_break,
|
||
segment_tree: ref _segment_tree,
|
||
} = state
|
||
{
|
||
cur_index = line_index;
|
||
within_line_index = _within_line_index;
|
||
breaks = _breaks;
|
||
prev_break = _prev_break;
|
||
|
||
segment_tree = _segment_tree;
|
||
} else {
|
||
unreachable!()
|
||
}
|
||
}
|
||
LineBreakTextState::WithinLine {
|
||
ref mut line_index,
|
||
ref line_length,
|
||
within_line_index: ref mut _within_line_index,
|
||
breaks: ref _breaks,
|
||
prev_break: ref mut _prev_break,
|
||
segment_tree: ref _segment_tree,
|
||
} => {
|
||
line = &self.text[*line_index..(*line_index + *line_length)];
|
||
cur_index = line_index;
|
||
within_line_index = _within_line_index;
|
||
breaks = _breaks;
|
||
prev_break = _prev_break;
|
||
segment_tree = _segment_tree;
|
||
}
|
||
}
|
||
|
||
if segment_tree.get_sum(0, line.len()) <= width {
|
||
*state = LineBreakTextState::AtLine {
|
||
cur_index: *cur_index + line.len() + 1,
|
||
};
|
||
return Some(
|
||
line.trim_end_matches(|c| c == '\r' || c == '\n')
|
||
.to_string(),
|
||
);
|
||
}
|
||
if breaks.len() < 2 {
|
||
let mut line = line;
|
||
while !line.is_empty() {
|
||
let mut chop_index = std::cmp::min(line.len().saturating_sub(1), width);
|
||
while chop_index > 0 && !line.is_char_boundary(chop_index) {
|
||
chop_index -= 1;
|
||
}
|
||
if chop_index == 0 {
|
||
self.paragraph.push_back(format!("⤷{}", line));
|
||
*cur_index += line.len();
|
||
break;
|
||
} else {
|
||
self.paragraph
|
||
.push_back(format!("⤷{}", &line[..chop_index]));
|
||
*cur_index += chop_index;
|
||
}
|
||
line = &line[chop_index..];
|
||
}
|
||
*state = LineBreakTextState::AtLine {
|
||
cur_index: *cur_index,
|
||
};
|
||
if !self.paragraph.is_empty() {
|
||
return self.paragraph.pop_front();
|
||
}
|
||
continue;
|
||
}
|
||
|
||
while *prev_break < breaks.len() {
|
||
let new_off = match breaks[*prev_break..].binary_search_by(|(offset, _)| {
|
||
segment_tree
|
||
.get_sum(*within_line_index, offset.saturating_sub(1))
|
||
.cmp(&width)
|
||
}) {
|
||
Ok(v) => v,
|
||
Err(v) => v,
|
||
} + *prev_break;
|
||
let end_offset = if new_off >= breaks.len() {
|
||
line.len()
|
||
} else {
|
||
breaks[new_off].0
|
||
};
|
||
if !line[*within_line_index..end_offset].is_empty() {
|
||
if *within_line_index == 0 {
|
||
let ret = line[*within_line_index..end_offset]
|
||
.trim_end_matches(|c| c == '\r' || c == '\n');
|
||
*within_line_index = end_offset;
|
||
return Some(ret.to_string());
|
||
} else {
|
||
let ret = format!(
|
||
"⤷{}",
|
||
&line[*within_line_index..end_offset]
|
||
.trim_end_matches(|c| c == '\r' || c == '\n')
|
||
);
|
||
*within_line_index = end_offset;
|
||
return Some(ret);
|
||
}
|
||
}
|
||
if *within_line_index == end_offset && *prev_break == new_off {
|
||
break;
|
||
}
|
||
*within_line_index = end_offset + 1;
|
||
*prev_break = new_off;
|
||
}
|
||
*state = LineBreakTextState::AtLine {
|
||
cur_index: *cur_index + line.len() + 1,
|
||
};
|
||
}
|
||
}
|
||
ReflowState::No { ref mut cur_index } | ReflowState::All { ref mut cur_index } => {
|
||
if let Some(line) = self.text[*cur_index..].split('\n').next() {
|
||
let ret = line.to_string();
|
||
*cur_index += line.len() + 2;
|
||
return Some(ret);
|
||
}
|
||
return None;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
fn reflow_helper2(
|
||
ret: &mut VecDeque<String>,
|
||
paragraph: &str,
|
||
quote_depth: usize,
|
||
in_paragraph: bool,
|
||
width: Option<usize>,
|
||
) {
|
||
if quote_depth > 0 {
|
||
let quotes: String = ">".repeat(quote_depth);
|
||
let paragraph = paragraph
|
||
.trim_start_matches("es)
|
||
.replace(&format!("\n{}", "es), "")
|
||
.replace("\n", "")
|
||
.replace("\r", "");
|
||
if in_paragraph {
|
||
if let Some(width) = width {
|
||
ret.extend(
|
||
linear(¶graph, width.saturating_sub(quote_depth))
|
||
.into_iter()
|
||
.map(|l| format!("{}{}", "es, l)),
|
||
);
|
||
} else {
|
||
ret.push_back(format!("{}{}", "es, ¶graph));
|
||
}
|
||
} else {
|
||
ret.push_back(format!("{}{}", "es, ¶graph));
|
||
}
|
||
} else {
|
||
let paragraph = paragraph.replace("\n", "").replace("\r", "");
|
||
|
||
if in_paragraph {
|
||
if let Some(width) = width {
|
||
let ex = linear(¶graph, width);
|
||
ret.extend(ex.into_iter());
|
||
} else {
|
||
ret.push_back(paragraph);
|
||
}
|
||
} else {
|
||
ret.push_back(paragraph);
|
||
}
|
||
}
|
||
}
|