led/src/string_utils.rs

106 lines
3.1 KiB
Rust

//! Misc helpful utility functions for TextBuffer related stuff.
use ropey::RopeSlice;
pub fn is_line_ending(text: &str) -> bool {
match text.chars().nth(0) {
Some(c) if (c >= '\u{000A}' && c <= '\u{000D}') => true,
Some('\u{0085}') | Some('\u{2028}') | Some('\u{2029}') => true,
_ => false,
}
}
pub fn str_is_whitespace(text: &str) -> bool {
if let Some(c) = text.chars().nth(0) {
is_whitespace(c)
} else {
false
}
}
pub fn is_whitespace(c: char) -> bool {
// TODO: this is a naive categorization of whitespace characters.
// For better categorization these should be split up into groups
// based on e.g. breaking vs non-breaking spaces, among other things.
match c {
//'\u{1680}' | // OGHAM SPACE MARK (here for completeness, but usually displayed as a dash, not as whitespace)
'\u{0009}' | // CHARACTER TABULATION
'\u{0020}' | // SPACE
'\u{00A0}' | // NO-BREAK SPACE
'\u{180E}' | // MONGOLIAN VOWEL SEPARATOR
'\u{202F}' | // NARROW NO-BREAK SPACE
'\u{205F}' | // MEDIUM MATHEMATICAL SPACE
'\u{3000}' | // IDEOGRAPHIC SPACE
'\u{FEFF}' // ZERO WIDTH NO-BREAK SPACE
=> true,
// EN QUAD, EM QUAD, EN SPACE, EM SPACE, THREE-PER-EM SPACE,
// FOUR-PER-EM SPACE, SIX-PER-EM SPACE, FIGURE SPACE,
// PUNCTUATION SPACE, THIN SPACE, HAIR SPACE, ZERO WIDTH SPACE.
c if c >= '\u{2000}' && c <= '\u{200B}' => true,
// Not a matching whitespace character.
_ => false,
}
}
/// Represents one of the valid Unicode line endings.
/// Also acts as an index into `LINE_ENDINGS`.
#[derive(PartialEq, Copy, Clone)]
pub enum LineEnding {
None = 0, // No line ending
CRLF = 1, // CarriageReturn followed by LineFeed
LF = 2, // U+000A -- LineFeed
VT = 3, // U+000B -- VerticalTab
FF = 4, // U+000C -- FormFeed
CR = 5, // U+000D -- CarriageReturn
NEL = 6, // U+0085 -- NextLine
LS = 7, // U+2028 -- Line Separator
PS = 8, // U+2029 -- ParagraphSeparator
}
pub fn str_to_line_ending(g: &str) -> LineEnding {
match g {
"\u{000D}\u{000A}" => LineEnding::CRLF,
"\u{000A}" => LineEnding::LF,
"\u{000B}" => LineEnding::VT,
"\u{000C}" => LineEnding::FF,
"\u{000D}" => LineEnding::CR,
"\u{0085}" => LineEnding::NEL,
"\u{2028}" => LineEnding::LS,
"\u{2029}" => LineEnding::PS,
// Not a line ending
_ => LineEnding::None,
}
}
pub fn rope_slice_to_line_ending(g: RopeSlice) -> LineEnding {
if let Some(text) = g.as_str() {
str_to_line_ending(text)
} else if g == "\u{000D}\u{000A}" {
LineEnding::CRLF
} else {
// Not a line ending
LineEnding::None
}
}
pub fn line_ending_to_str(ending: LineEnding) -> &'static str {
LINE_ENDINGS[ending as usize]
}
/// An array of string literals corresponding to the possible
/// unicode line endings.
pub const LINE_ENDINGS: [&'static str; 9] = [
"",
"\u{000D}\u{000A}",
"\u{000A}",
"\u{000B}",
"\u{000C}",
"\u{000D}",
"\u{0085}",
"\u{2028}",
"\u{2029}",
];