helix-mirror/helix-core/src/line_ending.rs
2021-10-24 17:28:29 +09:00

266 lines
9.0 KiB
Rust

use crate::{Rope, RopeSlice};
#[cfg(target_os = "windows")]
pub const DEFAULT_LINE_ENDING: LineEnding = LineEnding::Crlf;
#[cfg(not(target_os = "windows"))]
pub const DEFAULT_LINE_ENDING: LineEnding = LineEnding::LF;
/// Represents one of the valid Unicode line endings.
#[derive(PartialEq, Copy, Clone, Debug)]
pub enum LineEnding {
Crlf, // CarriageReturn followed by LineFeed
LF, // U+000A -- LineFeed
VT, // U+000B -- VerticalTab
FF, // U+000C -- FormFeed
CR, // U+000D -- CarriageReturn
Nel, // U+0085 -- NextLine
LS, // U+2028 -- Line Separator
PS, // U+2029 -- ParagraphSeparator
}
impl LineEnding {
#[inline]
pub const fn len_chars(&self) -> usize {
match self {
Self::Crlf => 2,
_ => 1,
}
}
#[inline]
pub const fn as_str(&self) -> &'static str {
match self {
Self::Crlf => "\u{000D}\u{000A}",
Self::LF => "\u{000A}",
Self::VT => "\u{000B}",
Self::FF => "\u{000C}",
Self::CR => "\u{000D}",
Self::Nel => "\u{0085}",
Self::LS => "\u{2028}",
Self::PS => "\u{2029}",
}
}
#[inline]
pub const fn from_char(ch: char) -> Option<LineEnding> {
match ch {
'\u{000A}' => Some(LineEnding::LF),
'\u{000B}' => Some(LineEnding::VT),
'\u{000C}' => Some(LineEnding::FF),
'\u{000D}' => Some(LineEnding::CR),
'\u{0085}' => Some(LineEnding::Nel),
'\u{2028}' => Some(LineEnding::LS),
'\u{2029}' => Some(LineEnding::PS),
// Not a line ending
_ => None,
}
}
// Normally we'd want to implement the FromStr trait, but in this case
// that would force us into a different return type than from_char or
// or from_rope_slice, which would be weird.
#[allow(clippy::should_implement_trait)]
#[inline]
pub fn from_str(g: &str) -> Option<LineEnding> {
match g {
"\u{000D}\u{000A}" => Some(LineEnding::Crlf),
"\u{000A}" => Some(LineEnding::LF),
"\u{000B}" => Some(LineEnding::VT),
"\u{000C}" => Some(LineEnding::FF),
"\u{000D}" => Some(LineEnding::CR),
"\u{0085}" => Some(LineEnding::Nel),
"\u{2028}" => Some(LineEnding::LS),
"\u{2029}" => Some(LineEnding::PS),
// Not a line ending
_ => None,
}
}
#[inline]
pub fn from_rope_slice(g: &RopeSlice) -> Option<LineEnding> {
if let Some(text) = g.as_str() {
LineEnding::from_str(text)
} else {
// Non-contiguous, so it can't be a line ending.
// Specifically, Ropey guarantees that CRLF is always
// contiguous. And the remaining line endings are all
// single `char`s, and therefore trivially contiguous.
None
}
}
}
#[inline]
pub fn str_is_line_ending(s: &str) -> bool {
LineEnding::from_str(s).is_some()
}
/// Attempts to detect what line ending the passed document uses.
pub fn auto_detect_line_ending(doc: &Rope) -> Option<LineEnding> {
// Return first matched line ending. Not all possible line endings
// are being matched, as they might be special-use only
for line in doc.lines().take(100) {
match get_line_ending(&line) {
None | Some(LineEnding::VT) | Some(LineEnding::FF) | Some(LineEnding::PS) => {}
ending => return ending,
}
}
None
}
/// Returns the passed line's line ending, if any.
pub fn get_line_ending(line: &RopeSlice) -> Option<LineEnding> {
// Last character as str.
let g1 = line
.slice(line.len_chars().saturating_sub(1)..)
.as_str()
.unwrap();
// Last two characters as str, or empty str if they're not contiguous.
// It's fine to punt on the non-contiguous case, because Ropey guarantees
// that CRLF is always contiguous.
let g2 = line
.slice(line.len_chars().saturating_sub(2)..)
.as_str()
.unwrap_or("");
// First check the two-character case for CRLF, then check the single-character case.
LineEnding::from_str(g2).or_else(|| LineEnding::from_str(g1))
}
/// Returns the passed line's line ending, if any.
pub fn get_line_ending_of_str(line: &str) -> Option<LineEnding> {
if line.ends_with("\u{000D}\u{000A}") {
Some(LineEnding::Crlf)
} else if line.ends_with('\u{000A}') {
Some(LineEnding::LF)
} else if line.ends_with('\u{000B}') {
Some(LineEnding::VT)
} else if line.ends_with('\u{000C}') {
Some(LineEnding::FF)
} else if line.ends_with('\u{000D}') {
Some(LineEnding::CR)
} else if line.ends_with('\u{0085}') {
Some(LineEnding::Nel)
} else if line.ends_with('\u{2028}') {
Some(LineEnding::LS)
} else if line.ends_with('\u{2029}') {
Some(LineEnding::PS)
} else {
None
}
}
/// Returns the char index of the end of the given line, not including its line ending.
pub fn line_end_char_index(slice: &RopeSlice, line: usize) -> usize {
slice.line_to_char(line + 1)
- get_line_ending(&slice.line(line))
.map(|le| le.len_chars())
.unwrap_or(0)
}
/// Fetches line `line_idx` from the passed rope slice, sans any line ending.
pub fn line_without_line_ending<'a>(slice: &'a RopeSlice, line_idx: usize) -> RopeSlice<'a> {
let start = slice.line_to_char(line_idx);
let end = line_end_char_index(slice, line_idx);
slice.slice(start..end)
}
/// Returns the char index of the end of the given RopeSlice, not including
/// any final line ending.
pub fn rope_end_without_line_ending(slice: &RopeSlice) -> usize {
slice.len_chars() - get_line_ending(slice).map(|le| le.len_chars()).unwrap_or(0)
}
#[cfg(test)]
mod line_ending_tests {
use super::*;
#[test]
fn line_ending_autodetect() {
assert_eq!(
auto_detect_line_ending(&Rope::from_str("\n")),
Some(LineEnding::LF)
);
assert_eq!(
auto_detect_line_ending(&Rope::from_str("\r\n")),
Some(LineEnding::Crlf)
);
assert_eq!(auto_detect_line_ending(&Rope::from_str("hello")), None);
assert_eq!(auto_detect_line_ending(&Rope::from_str("")), None);
assert_eq!(
auto_detect_line_ending(&Rope::from_str("hello\nhelix\r\n")),
Some(LineEnding::LF)
);
assert_eq!(
auto_detect_line_ending(&Rope::from_str("a formfeed\u{000C}")),
None
);
assert_eq!(
auto_detect_line_ending(&Rope::from_str("\n\u{000A}\n \u{000A}")),
Some(LineEnding::LF)
);
assert_eq!(
auto_detect_line_ending(&Rope::from_str(
"a formfeed\u{000C} with a\u{000C} linefeed\u{000A}"
)),
Some(LineEnding::LF)
);
assert_eq!(auto_detect_line_ending(&Rope::from_str("a formfeed\u{000C} with a\u{000C} carriage return linefeed\u{000D}\u{000A} and a linefeed\u{000A}")), Some(LineEnding::Crlf));
}
#[test]
fn str_to_line_ending() {
assert_eq!(LineEnding::from_str("\r"), Some(LineEnding::CR));
assert_eq!(LineEnding::from_str("\n"), Some(LineEnding::LF));
assert_eq!(LineEnding::from_str("\r\n"), Some(LineEnding::Crlf));
assert_eq!(LineEnding::from_str("hello\n"), None);
}
#[test]
fn rope_slice_to_line_ending() {
let r = Rope::from_str("hello\r\n");
assert_eq!(
LineEnding::from_rope_slice(&r.slice(5..6)),
Some(LineEnding::CR)
);
assert_eq!(
LineEnding::from_rope_slice(&r.slice(6..7)),
Some(LineEnding::LF)
);
assert_eq!(
LineEnding::from_rope_slice(&r.slice(5..7)),
Some(LineEnding::Crlf)
);
assert_eq!(LineEnding::from_rope_slice(&r.slice(..)), None);
}
#[test]
fn get_line_ending_rope_slice() {
let r = Rope::from_str("Hello\rworld\nhow\r\nare you?");
assert_eq!(get_line_ending(&r.slice(..6)), Some(LineEnding::CR));
assert_eq!(get_line_ending(&r.slice(..12)), Some(LineEnding::LF));
assert_eq!(get_line_ending(&r.slice(..17)), Some(LineEnding::Crlf));
assert_eq!(get_line_ending(&r.slice(..)), None);
}
#[test]
fn get_line_ending_str() {
let text = "Hello\rworld\nhow\r\nare you?";
assert_eq!(get_line_ending_of_str(&text[..6]), Some(LineEnding::CR));
assert_eq!(get_line_ending_of_str(&text[..12]), Some(LineEnding::LF));
assert_eq!(get_line_ending_of_str(&text[..17]), Some(LineEnding::Crlf));
assert_eq!(get_line_ending_of_str(&text[..]), None);
}
#[test]
fn line_end_char_index_rope_slice() {
let r = Rope::from_str("Hello\rworld\nhow\r\nare you?");
let s = &r.slice(..);
assert_eq!(line_end_char_index(s, 0), 5);
assert_eq!(line_end_char_index(s, 1), 11);
assert_eq!(line_end_char_index(s, 2), 15);
assert_eq!(line_end_char_index(s, 3), 25);
}
}