Function is_valid_unicode

datafusion/pruning/src/pruning_predicate.rs:1965–1979

Helper function to check if a character is valid to use

(c: char)

fn increment_utf8(data: &str) -> Option<String> {
    // Helper function to check if a character is valid to use
    fn is_valid_unicode(c: char) -> bool {
        let cp = c as u32;

        // Filter out non-characters (https://www.unicode.org/versions/corrigendum9.html)
        if [0xFFFE, 0xFFFF].contains(&cp) || (0xFDD0..=0xFDEF).contains(&cp) {
            return false;
        }

        // Filter out private use area
        if cp >= 0x110000 {
            return false;
        }

        true
    }

    // Convert string to vector of code points
    let mut code_points: Vec<char> = data.chars().collect();