Function char_count_or_boundary

datafusion/functions/src/unicode/common.rs:95–104

(string: &str, n: usize)

/// the `n`-th codepoint boundary. Otherwise returns the total codepoint count.
#[inline]
pub(crate) fn char_count_or_boundary(string: &str, n: usize) -> StringCharLen {
    let mut count = 0;
    for (byte_idx, _) in string.char_indices() {
        if count == n {
            return StringCharLen::ByteOffset(byte_idx);
        }
        count += 1;
    }
    StringCharLen::CharCount(count)
}

/// Result of [`char_count_or_boundary`].
pub(crate) enum StringCharLen {