text_processing: add line_break method

In preparation for format=flowed support, add a line_break method in the
text_processing Trait, now renamed from Graphemes to TextProcessing.
jmap
Manos Pitsidianakis 2019-11-09 17:44:22 +02:00
parent 098982015b
commit e600b0252f
Signed by: Manos Pitsidianakis
GPG Key ID: 73627C2F690DF710
7 changed files with 197 additions and 32 deletions

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@ -1,7 +1,7 @@
use super::*;
#[cfg(feature = "unicode_algorithms")]
use text_processing::grapheme_clusters::Graphemes;
use text_processing::grapheme_clusters::TextProcessing;
pub fn encode_header(value: &str) -> String {
let mut ret = String::with_capacity(value.len());

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@ -12,7 +12,7 @@ use crate::wcwidth::{wcwidth, CodePointsIter};
extern crate unicode_segmentation;
use self::unicode_segmentation::UnicodeSegmentation;
pub trait Graphemes: UnicodeSegmentation + CodePointsIter {
pub trait TextProcessing: UnicodeSegmentation + CodePointsIter {
fn split_graphemes<'a>(&'a self) -> Vec<&'a str> {
UnicodeSegmentation::graphemes(self, true).collect::<Vec<&str>>()
}
@ -41,9 +41,15 @@ pub trait Graphemes: UnicodeSegmentation + CodePointsIter {
fn grapheme_len(&self) -> usize {
self.split_graphemes().len()
}
fn split_lines(&self, width: usize) -> Vec<String>;
}
impl Graphemes for str {}
impl TextProcessing for str {
fn split_lines(&self, width: usize) -> Vec<String> {
crate::line_break::linear(self, width)
}
}
pub struct WordBreakIter<'s> {
input: &'s str,

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@ -699,5 +699,179 @@ mod tests {
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::*;
use crate::grapheme_clusters::TextProcessing;
fn cost(i: usize, j: usize, width: usize, minima: &Vec<usize>, offsets: &Vec<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: &Vec<usize>,
) {
let mut stack = Vec::new();
let mut i = 0;
while i < rows.len() {
if stack.len() > 0 {
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 i in breaks[j]..j {
line.push_str(words[i]);
}
lines.push(line);
if p_i + 1 < paragraphs {
lines.push(String::new());
p_i += 1;
}
j = breaks[j];
}
lines.reverse();
lines
}
}

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@ -622,12 +622,7 @@ impl Component for MailView {
.map(|v| String::from_utf8_lossy(v).into_owned())
.unwrap_or_else(|e| e.to_string())
};
self.pager = Some(Pager::from_string(
text,
Some(context),
None,
Some(width!(area)),
));
self.pager = Some(Pager::from_string(text, Some(context), None, None));
self.subview = None;
}
_ => {
@ -643,12 +638,7 @@ impl Component for MailView {
} else {
self.pager.as_mut().map(|p| p.cursor_pos())
};
self.pager = Some(Pager::from_string(
text,
Some(context),
cursor_pos,
Some(width!(area)),
));
self.pager = Some(Pager::from_string(text, Some(context), cursor_pos, None));
self.subview = None;
}
};

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@ -339,12 +339,7 @@ impl Component for EnvelopeView {
} else {
self.pager.as_ref().map(Pager::cursor_pos)
};
self.pager = Some(Pager::from_string(
text,
Some(context),
cursor_pos,
Some(width!(area)),
));
self.pager = Some(Pager::from_string(text, Some(context), cursor_pos, None));
}
};
self.dirty = false;

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@ -297,10 +297,10 @@ impl fmt::Display for Pager {
impl Pager {
const DESCRIPTION: &'static str = "pager";
pub fn update_from_str(&mut self, text: &str, width: Option<usize>) {
let lines: Vec<&str> = if let Some(width) = width {
word_break_string(text, width)
let lines: Vec<String> = if let Some(width) = width {
text.split_lines(width)
} else {
text.trim().split('\n').collect()
text.trim().split('\n').map(str::to_string).collect()
};
let height = lines.len() + 1;
@ -355,10 +355,10 @@ impl Pager {
}
let content = {
let lines: Vec<&str> = if let Some(width) = width {
word_break_string(text.as_str(), width)
let lines: Vec<String> = if let Some(width) = width {
text.split_lines(width)
} else {
text.trim().split('\n').collect()
text.trim().split('\n').map(str::to_string).collect()
};
let height = lines.len() + 1;
@ -384,10 +384,10 @@ impl Pager {
}
}
pub fn from_str(text: &str, cursor_pos: Option<usize>, width: Option<usize>) -> Self {
let lines: Vec<&str> = if let Some(width) = width {
word_break_string(text, width)
let lines: Vec<String> = if let Some(width) = width {
text.split_lines(width)
} else {
text.trim().split('\n').collect()
text.trim().split('\n').map(str::to_string).collect()
};
let height = lines.len() + 1;
@ -419,7 +419,7 @@ impl Pager {
..Default::default()
}
}
pub fn print_string(content: &mut CellBuffer, lines: Vec<&str>) {
pub fn print_string(content: &mut CellBuffer, lines: Vec<String>) {
let width = content.size().0;
for (i, l) in lines.iter().enumerate() {
write_string_to_grid(

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@ -1,4 +1,4 @@
use text_processing::Graphemes;
use text_processing::TextProcessing;
#[derive(Debug, Clone, Default, PartialEq)]
pub struct UText {