Function line_span::find_prev_line_end

pub fn find_prev_line_end(text: &str, index: usize) -> Option<usize>

Find the end (byte index) of the previous line, the line before the one which index is within.

Note the end is the last character, excluding \n and \r\n.

Returns None if there is no previous line.

See also

• find_prev_line_range to find both start and end of the previous line.
• find_prev_line_start to find the start of the previous line.
• find_line_start to find the start of the current line.
• find_next_line_start to find the start of the next line.

Panics

Panics if index is out of bounds.

Example

let text = "foo\nbar\nbaz";
let i = 9; // 'a'

let end = line_span::find_prev_line_end(text, i).unwrap();

assert_eq!(end, 7);
assert_eq!(&text[..end], "foo\nbar");