Function utf16_col_to_byte_offset

src/util.rs:383–392

Convert a UTF-16 column offset to a byte offset within a single line. LSP positions use UTF-16 code units for the character offset. When a line contains multi-byte characters (e.g. `ń` is 2 bytes in UTF-8 but 1 UTF-16 code unit), the two offsets diverge. This helper walks the line counting UTF-16 code units and returns the corresponding byte position. Returns `line.len()` if `utf16_col` is pas

(line: &str, utf16_col: u32)

///
/// Returns `line.len()` if `utf16_col` is past the end of the line.
pub(crate) fn utf16_col_to_byte_offset(line: &str, utf16_col: u32) -> usize {
    let mut col = 0u32;
    for (i, ch) in line.char_indices() {
        if col == utf16_col {
            return i;
        }
        col += ch.len_utf16() as u32;
    }
    line.len()
}

/// Convert a byte offset within a single line to a UTF-16 column offset.
///