hecto/src/row.rs

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Rust
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use std::cmp;
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use unicode_segmentation::UnicodeSegmentation;
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#[derive(Default)]
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pub struct Row {
string: String,
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len: usize,
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}
impl From<&str> for Row {
fn from(slice: &str) -> Self {
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let mut row = Self {
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string: String::from(slice),
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len: 0,
};
row.update_len();
row
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}
}
impl Row {
pub fn render(&self, start: usize, end: usize) -> String {
let end = cmp::min(end, self.string.len());
let start = cmp::min(start, end);
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let mut result = String::new();
for grapheme in self.string[..]
.graphemes(true)
.skip(start)
.take(end - start)
{
if grapheme == "\t" {
result.push_str(" ");
} else {
result.push_str(grapheme);
}
}
result
}
pub fn len(&self) -> usize {
self.len
}
pub fn is_empty(&self) -> bool {
self.len == 0
}
fn update_len(&mut self) {
self.len = self.string[..].graphemes(true).count();
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}
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pub fn insert(&mut self, at: usize, c: char) {
if at >= self.len() {
self.string.push(c);
} else {
let mut result: String = self.string[..].graphemes(true).take(at).collect();
let remainder: String = self.string[..].graphemes(true).skip(at).collect();
result.push(c);
result.push_str(&remainder);
self.string = result;
}
self.update_len();
}
pub fn delete(&mut self, at: usize) {
if at >= self.len() {
return
} else {
let mut result: String = self.string[..].graphemes(true).take(at).collect();
let remainder: String = self.string[..].graphemes(true).skip(at + 1).collect();
result.push_str(&remainder);
self.string = result;
}
self.update_len();
}
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pub fn append(&mut self, new: &Self) {
self.string = format!("{}{}", self.string, new.string);
self.update_len();
}
pub fn split(&mut self, at: usize) -> Self {
let beginning: String = self.string[..].graphemes(true).take(at).collect();
let remainder: String = self.string[..].graphemes(true).skip(at).collect();
self.string = beginning;
self.update_len();
Self::from(&remainder[..])
}
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}