helix/helix-stdx/src/rope.rs

458 lines
16 KiB
Rust

use std::ops::{Bound, RangeBounds};
pub use regex_cursor::engines::meta::{Builder as RegexBuilder, Regex};
pub use regex_cursor::regex_automata::util::syntax::Config;
use regex_cursor::Input as RegexInput;
use ropey::{ChunkCursor, RopeSlice};
use unicode_segmentation::{GraphemeCursor, GraphemeIncomplete};
pub const LINE_TYPE: ropey::LineType = ropey::LineType::LF_CR;
pub trait RopeSliceExt<'a>: Sized {
fn ends_with(self, text: &str) -> bool;
fn starts_with(self, text: &str) -> bool;
fn regex_input(self) -> RegexInput<ChunkCursor<'a>>;
fn regex_input_at_bytes<R: RangeBounds<usize>>(
self,
byte_range: R,
) -> RegexInput<ChunkCursor<'a>>;
#[deprecated = "use regex_input_at_bytes instead"]
fn regex_input_at<R: RangeBounds<usize>>(self, char_range: R) -> RegexInput<ChunkCursor<'a>>;
fn first_non_whitespace_char(self) -> Option<usize>;
fn last_non_whitespace_char(self) -> Option<usize>;
/// Finds the closest byte index not exceeding `byte_idx` which lies on a grapheme cluster
/// boundary.
///
/// If `byte_idx` already lies on a grapheme cluster boundary then it is returned as-is. When
/// `byte_idx` lies between two grapheme cluster boundaries, this function returns the byte
/// index of the lesser / earlier / left-hand-side boundary.
///
/// `byte_idx` does not need to be aligned to a character boundary.
///
/// # Example
///
/// ```
/// # use ropey::{RopeSlice, Rope};
/// # use helix_stdx::rope::RopeSliceExt;
/// let text = Rope::from_str("\r\n"); // U+000D U+000A, hex: 0d 0a
/// let text = text.slice(..);
/// assert_eq!(text.floor_grapheme_boundary(0), 0);
/// assert_eq!(text.floor_grapheme_boundary(1), 0);
/// assert_eq!(text.floor_grapheme_boundary(2), 2);
/// ```
fn floor_grapheme_boundary(self, byte_idx: usize) -> usize;
fn prev_grapheme_boundary(self, byte_idx: usize) -> usize {
self.nth_prev_grapheme_boundary(byte_idx, 1)
}
fn nth_prev_grapheme_boundary(self, byte_idx: usize, n: usize) -> usize;
/// Finds the closest byte index not exceeding `byte_idx` which lies on a grapheme cluster
/// boundary.
///
/// If `byte_idx` already lies on a grapheme cluster boundary then it is returned as-is. When
/// `byte_idx` lies between two grapheme cluster boundaries, this function returns the byte
/// index of the greater / later / right-hand-side boundary.
///
/// `byte_idx` does not need to be aligned to a character boundary.
///
/// # Example
///
/// ```
/// # use ropey::{RopeSlice, Rope};
/// # use helix_stdx::rope::RopeSliceExt;
/// let text = Rope::from_str("\r\n"); // U+000D U+000A, hex: 0d 0a
/// let text = text.slice(..);
/// assert_eq!(text.ceil_grapheme_boundary(0), 0);
/// assert_eq!(text.ceil_grapheme_boundary(1), 2);
/// assert_eq!(text.ceil_grapheme_boundary(2), 2);
/// ```
fn ceil_grapheme_boundary(self, byte_idx: usize) -> usize;
fn next_grapheme_boundary(self, byte_idx: usize) -> usize {
self.nth_next_grapheme_boundary(byte_idx, 1)
}
fn nth_next_grapheme_boundary(self, byte_idx: usize, n: usize) -> usize;
/// Checks whether the `byte_idx` lies on a grapheme cluster boundary.
///
/// # Example
///
/// ```
/// # use ropey::{RopeSlice, Rope};
/// # use helix_stdx::rope::RopeSliceExt;
/// let text = Rope::from_str("\r\n"); // U+000D U+000A, hex: 0d 0a
/// let text = text.slice(..);
/// assert!(text.is_grapheme_boundary(0));
/// assert!(!text.is_grapheme_boundary(1));
/// assert!(text.is_grapheme_boundary(2));
/// ```
#[allow(clippy::wrong_self_convention)]
fn is_grapheme_boundary(self, byte_idx: usize) -> bool;
/// Returns an iterator over the grapheme clusters in the slice.
///
/// # Example
///
/// ```
/// # use ropey::{RopeSlice, Rope};
/// # use helix_stdx::rope::RopeSliceExt;
/// let text = Rope::from_str("😶‍🌫️🏴‍☠️🖼️");
/// let graphemes: Vec<_> = text.slice(..).graphemes().collect();
/// assert_eq!(graphemes.as_slice(), &["😶‍🌫️", "🏴‍☠️", "🖼️"]);
/// ```
fn graphemes(self) -> RopeGraphemes<'a>;
/// Returns an iterator over the grapheme clusters in the slice, reversed.
///
/// The returned iterator starts at the end of the slice and ends at the beginning of the
/// slice.
///
/// # Example
///
/// ```
/// # use ropey::{RopeSlice, Rope};
/// # use helix_stdx::rope::RopeSliceExt;
/// let text = Rope::from_str("😶‍🌫️🏴‍☠️🖼️");
/// let graphemes: Vec<_> = text.slice(..).graphemes_rev().collect();
/// assert_eq!(graphemes.as_slice(), &["🖼️", "🏴‍☠️", "😶‍🌫️"]);
/// ```
fn graphemes_rev(self) -> RevRopeGraphemes<'a>;
}
impl<'a> RopeSliceExt<'a> for RopeSlice<'a> {
fn ends_with(self, text: &str) -> bool {
let len = self.len();
if len < text.len() {
return false;
}
self.try_slice(len - text.len()..)
.is_ok_and(|end| end == text)
}
fn starts_with(self, text: &str) -> bool {
let len = self.len();
if len < text.len() {
return false;
}
self.try_slice(..text.len())
.is_ok_and(|start| start == text)
}
fn regex_input(self) -> RegexInput<ChunkCursor<'a>> {
RegexInput::new(self)
}
fn regex_input_at<R: RangeBounds<usize>>(self, char_range: R) -> RegexInput<ChunkCursor<'a>> {
let start_bound = match char_range.start_bound() {
Bound::Included(&val) => Bound::Included(self.char_to_byte_idx(val)),
Bound::Excluded(&val) => Bound::Excluded(self.char_to_byte_idx(val)),
Bound::Unbounded => Bound::Unbounded,
};
let end_bound = match char_range.end_bound() {
Bound::Included(&val) => Bound::Included(self.char_to_byte_idx(val)),
Bound::Excluded(&val) => Bound::Excluded(self.char_to_byte_idx(val)),
Bound::Unbounded => Bound::Unbounded,
};
self.regex_input_at_bytes((start_bound, end_bound))
}
fn regex_input_at_bytes<R: RangeBounds<usize>>(
self,
byte_range: R,
) -> RegexInput<ChunkCursor<'a>> {
let input = match byte_range.start_bound() {
Bound::Included(&pos) | Bound::Excluded(&pos) => {
RegexInput::new(self.chunk_cursor_at(pos))
}
Bound::Unbounded => RegexInput::new(self),
};
input.range(byte_range)
}
fn first_non_whitespace_char(self) -> Option<usize> {
self.chars().position(|ch| !ch.is_whitespace())
}
fn last_non_whitespace_char(self) -> Option<usize> {
self.chars_at(self.len_chars())
.reversed()
.position(|ch| !ch.is_whitespace())
.map(|pos| self.len_chars() - pos - 1)
}
fn floor_grapheme_boundary(self, mut byte_idx: usize) -> usize {
if byte_idx >= self.len() {
return self.len();
}
byte_idx = self.ceil_char_boundary(byte_idx + 1);
let mut chunk_cursor = self.chunk_cursor_at(byte_idx);
let mut cursor = GraphemeCursor::new(byte_idx, self.len(), true);
loop {
match cursor.prev_boundary(chunk_cursor.chunk(), chunk_cursor.byte_offset()) {
Ok(None) => return 0,
Ok(Some(boundary)) => return boundary,
Err(GraphemeIncomplete::PrevChunk) => assert!(chunk_cursor.prev()),
Err(GraphemeIncomplete::PreContext(n)) => {
let ctx_chunk = self.chunk(n - 1).0;
cursor.provide_context(ctx_chunk, n - ctx_chunk.len());
}
_ => unreachable!(),
}
}
}
fn nth_prev_grapheme_boundary(self, mut byte_idx: usize, n: usize) -> usize {
byte_idx = self.floor_char_boundary(byte_idx);
let mut chunk_cursor = self.chunk_cursor_at(byte_idx);
let mut cursor = GraphemeCursor::new(byte_idx, self.len(), true);
for _ in 0..n {
loop {
match cursor.prev_boundary(chunk_cursor.chunk(), chunk_cursor.byte_offset()) {
Ok(None) => return 0,
Ok(Some(boundary)) => {
byte_idx = boundary;
break;
}
Err(GraphemeIncomplete::PrevChunk) => assert!(chunk_cursor.prev()),
Err(GraphemeIncomplete::PreContext(n)) => {
let ctx_chunk = self.chunk(n - 1).0;
cursor.provide_context(ctx_chunk, n - ctx_chunk.len());
}
_ => unreachable!(),
}
}
}
byte_idx
}
fn ceil_grapheme_boundary(self, mut byte_idx: usize) -> usize {
if byte_idx >= self.len() {
return self.len();
}
if byte_idx == 0 {
return 0;
}
byte_idx = self.floor_char_boundary(byte_idx - 1);
let mut chunk_cursor = self.chunk_cursor_at(byte_idx);
let mut cursor = GraphemeCursor::new(byte_idx, self.len(), true);
loop {
match cursor.next_boundary(chunk_cursor.chunk(), chunk_cursor.byte_offset()) {
Ok(None) => return self.len(),
Ok(Some(boundary)) => return boundary,
Err(GraphemeIncomplete::NextChunk) => assert!(chunk_cursor.next()),
Err(GraphemeIncomplete::PreContext(n)) => {
let ctx_chunk = self.chunk(n - 1).0;
cursor.provide_context(ctx_chunk, n - ctx_chunk.len());
}
_ => unreachable!(),
}
}
}
fn nth_next_grapheme_boundary(self, mut byte_idx: usize, n: usize) -> usize {
byte_idx = self.ceil_char_boundary(byte_idx);
let mut chunk_cursor = self.chunk_cursor_at(byte_idx);
let mut cursor = GraphemeCursor::new(byte_idx, self.len(), true);
for _ in 0..n {
loop {
match cursor.prev_boundary(chunk_cursor.chunk(), chunk_cursor.byte_offset()) {
Ok(None) => return 0,
Ok(Some(boundary)) => {
byte_idx = boundary;
break;
}
Err(GraphemeIncomplete::NextChunk) => assert!(chunk_cursor.next()),
Err(GraphemeIncomplete::PreContext(n)) => {
let ctx_chunk = self.chunk(n - 1).0;
cursor.provide_context(ctx_chunk, n - ctx_chunk.len());
}
_ => unreachable!(),
}
}
}
byte_idx
}
fn is_grapheme_boundary(self, byte_idx: usize) -> bool {
// The byte must lie on a character boundary to lie on a grapheme cluster boundary.
if !self.is_char_boundary(byte_idx) {
return false;
}
let (chunk, chunk_byte_idx) = self.chunk(byte_idx);
let mut cursor = GraphemeCursor::new(byte_idx, self.len(), true);
loop {
match cursor.is_boundary(chunk, chunk_byte_idx) {
Ok(n) => return n,
Err(GraphemeIncomplete::PreContext(n)) => {
let (ctx_chunk, ctx_byte_start) = self.chunk(n - 1);
cursor.provide_context(ctx_chunk, ctx_byte_start);
}
Err(_) => unreachable!(),
}
}
}
fn graphemes(self) -> RopeGraphemes<'a> {
RopeGraphemes {
chunk_cursor: self.chunk_cursor(),
text: self,
cursor: GraphemeCursor::new(0, self.len(), true),
}
}
fn graphemes_rev(self) -> RevRopeGraphemes<'a> {
RevRopeGraphemes {
chunk_cursor: self.chunk_cursor_at(self.len()),
text: self,
cursor: GraphemeCursor::new(self.len(), self.len(), true),
}
}
}
/// An iterator over the graphemes of a `RopeSlice`.
#[derive(Debug, Clone)]
pub struct RopeGraphemes<'a> {
text: RopeSlice<'a>,
chunk_cursor: ChunkCursor<'a>,
cursor: GraphemeCursor,
}
impl<'a> Iterator for RopeGraphemes<'a> {
type Item = RopeSlice<'a>;
fn next(&mut self) -> Option<Self::Item> {
let a = self.cursor.cur_cursor();
let b;
loop {
match self
.cursor
.next_boundary(self.chunk_cursor.chunk(), self.chunk_cursor.byte_offset())
{
Ok(None) => {
return None;
}
Ok(Some(n)) => {
b = n;
break;
}
Err(GraphemeIncomplete::NextChunk) => assert!(self.chunk_cursor.next()),
Err(GraphemeIncomplete::PreContext(idx)) => {
let (chunk, byte_idx) = self.text.chunk(idx.saturating_sub(1));
self.cursor.provide_context(chunk, byte_idx);
}
_ => unreachable!(),
}
}
if a < self.chunk_cursor.byte_offset() {
Some(self.text.slice(a..b))
} else {
let a2 = a - self.chunk_cursor.byte_offset();
let b2 = b - self.chunk_cursor.byte_offset();
Some((&self.chunk_cursor.chunk()[a2..b2]).into())
}
}
}
/// An iterator over the graphemes of a `RopeSlice` in reverse.
#[derive(Debug, Clone)]
pub struct RevRopeGraphemes<'a> {
text: RopeSlice<'a>,
chunk_cursor: ChunkCursor<'a>,
cursor: GraphemeCursor,
}
impl<'a> Iterator for RevRopeGraphemes<'a> {
type Item = RopeSlice<'a>;
fn next(&mut self) -> Option<Self::Item> {
let a = self.cursor.cur_cursor();
let b;
loop {
match self
.cursor
.prev_boundary(self.chunk_cursor.chunk(), self.chunk_cursor.byte_offset())
{
Ok(None) => {
return None;
}
Ok(Some(n)) => {
b = n;
break;
}
Err(GraphemeIncomplete::PrevChunk) => assert!(self.chunk_cursor.prev()),
Err(GraphemeIncomplete::PreContext(idx)) => {
let (chunk, byte_idx) = self.text.chunk(idx.saturating_sub(1));
self.cursor.provide_context(chunk, byte_idx);
}
_ => unreachable!(),
}
}
if a >= self.chunk_cursor.byte_offset() + self.chunk_cursor.chunk().len() {
Some(self.text.slice(b..a))
} else {
let a2 = a - self.chunk_cursor.byte_offset();
let b2 = b - self.chunk_cursor.byte_offset();
Some((&self.chunk_cursor.chunk()[b2..a2]).into())
}
}
}
#[cfg(test)]
mod tests {
use ropey::RopeSlice;
use crate::rope::RopeSliceExt;
#[test]
fn starts_with() {
assert!(RopeSlice::from("asdf").starts_with("a"));
}
#[test]
fn ends_with() {
assert!(RopeSlice::from("asdf").ends_with("f"));
}
#[test]
fn grapheme_boundaries() {
let ascii = RopeSlice::from("ascii");
// When the given index lies on a grapheme boundary, the index should not change.
for byte_idx in 0..=ascii.len() {
assert_eq!(ascii.floor_char_boundary(byte_idx), byte_idx);
assert_eq!(ascii.ceil_char_boundary(byte_idx), byte_idx);
assert!(ascii.is_grapheme_boundary(byte_idx));
}
// 🏴‍☠️: U+1F3F4 U+200D U+2620 U+FE0F
// 13 bytes, hex: f0 9f 8f b4 + e2 80 8d + e2 98 a0 + ef b8 8f
let g = RopeSlice::from("🏴‍☠️\r\n");
let emoji_len = "🏴‍☠️".len();
let end = g.len();
for byte_idx in 0..emoji_len {
assert_eq!(g.floor_grapheme_boundary(byte_idx), 0);
}
for byte_idx in emoji_len..end {
assert_eq!(g.floor_grapheme_boundary(byte_idx), emoji_len);
}
assert_eq!(g.floor_grapheme_boundary(end), end);
assert_eq!(g.ceil_grapheme_boundary(0), 0);
for byte_idx in 1..=emoji_len {
assert_eq!(g.ceil_grapheme_boundary(byte_idx), emoji_len);
}
for byte_idx in emoji_len + 1..=end {
assert_eq!(g.ceil_grapheme_boundary(byte_idx), end);
}
assert!(g.is_grapheme_boundary(0));
assert!(g.is_grapheme_boundary(emoji_len));
assert!(g.is_grapheme_boundary(end));
for byte_idx in (1..emoji_len).chain(emoji_len + 1..end) {
assert!(!g.is_grapheme_boundary(byte_idx));
}
}
}