Function is_http_header_name

modules/llrt_fetch/src/headers.rs:659–671

(name: &str)

            b'!' | b'#' | b'$' | b'%' | b'&' | b'\'' | b'*' | b'+' |
            b'-' | b'.' | b'^' | b'_' | b'`' | b'|' | b'~' |
            b'0'..=b'9' | b'A'..=b'Z' | b'a'..=b'z'
        )
    })
}

/// Check for bare CR or LF in the interior of the value (not leading/trailing)
fn has_bare_cr_lf(value: &str) -> bool {
    let trimmed = value.trim_matches(|c: char| c == ' ' || c == '\t' || c == '\n' || c == '\r');
    trimmed.bytes().any(|b| b == b'\n' || b == b'\r')
}
fn is_http_header_value(value: &str) -> bool {
    value.chars().all(|c| {
        let cp = c as u32;
        cp == 0x09                          // HTAB
        || cp == 0x0C                       // Form Feed
        || (0x20..=0x7E).contains(&cp)      // SP + VCHAR