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/// Positional information about a start and end point in the text.
#[derive(Debug, PartialEq, Clone, Copy)]
pub struct Range {
/// Start position of the node in the text.
pub start: usize,
/// End position of the node in the text.
pub end: usize,
}
impl Range {
pub fn new(start: usize, end: usize) -> Self {
Range { start, end }
}
pub fn from_byte_index(pos: usize) -> Self {
Range::new(pos, pos)
}
}
impl Ranged for Range {
fn range(&self) -> Range {
*self
}
}
/// Represents an object that has a range in the text.
pub trait Ranged {
/// Gets the range.
fn range(&self) -> Range;
/// Gets the byte index of the first character in the text.
fn start(&self) -> usize {
self.range().start
}
/// Gets the byte index after the last character in the text.
fn end(&self) -> usize {
self.range().end
}
/// Gets the text from the provided string.
fn text<'a>(&self, text: &'a str) -> &'a str {
let range = self.range();
&text[range.start..range.end]
}
/// Gets the end byte index minus the start byte index of the range.
fn width(&self) -> usize {
let range = self.range();
range.end - range.start
}
}