Function col16

codegraph-kernel/src/textutil.rs:99–105

Column (UTF-16 units) of `byte_pos` on line `row`, given `line_starts`.

(src: &str, starts: &[usize], row: usize, byte_pos: usize)

/// Column (UTF-16 units) of `byte_pos` on line `row`, given `line_starts`.
pub fn col16(src: &str, starts: &[usize], row: usize, byte_pos: usize) -> u32 {
    let ls = starts.get(row).copied().unwrap_or(0);
    if byte_pos <= ls {
        return 0;
    }
    utf16_len(&src[ls..byte_pos]) as u32
}

/// JS `String.prototype.slice(0, n)` in UTF-16 units, without splitting a
/// surrogate pair (when the cut would split one, we stop one code unit short —