Function byte_index_to_char_index

std/src/strings.rs:82–84

Returns the number of characters before the given byte offset within `s`.

(s: &str, byte_index: usize)

/// Returns the number of characters before the given byte offset within `s`.
fn byte_index_to_char_index(s: &str, byte_index: usize) -> usize {
    s[..byte_index].chars().count()
}

/// Returns the number of characters in `s`.
fn char_len(s: &str) -> usize {