Function is_hex

regex/regex-syntax/src/ast/parse.rs:104–106

Returns true if the given character is a hexadecimal digit.

(c: char)

/// Returns true if the given character is a hexadecimal digit.
fn is_hex(c: char) -> bool {
    ('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')
}

/// Returns true if the given character is a valid in a capture group name.
///