#[macro_export]
macro_rules! char_class {
    ($c: expr, [$head:expr]) => ($c == $head);
    ($c: expr, [$head:expr $(, $cs:expr)+]) => ($c == $head || $crate::char_class!($c, [$($cs),*]));
}

#[macro_export]
macro_rules! alpha_char {
    ($c: expr) => {
        match $c {
            'a'..='z' => true,
            'A'..='Z' => true,
            '_' => true,
            '\u{00A0}'..='\u{00BF}' => true,
            '\u{00C0}'..='\u{00D6}' => true,
            '\u{00D8}'..='\u{00F6}' => true,
            '\u{00F8}'..='\u{00FF}' => true,
            '\u{0100}'..='\u{017F}' => true, // Latin Extended-A
            '\u{0180}'..='\u{024F}' => true, // Latin Extended-B
            '\u{0250}'..='\u{02AF}' => true, // IPA Extensions
            '\u{02B0}'..='\u{02FF}' => true, // Spacing Modifier Letters
            '\u{0300}'..='\u{036F}' => true, // Combining Diacritical Marks
            '\u{0370}'..='\u{03FF}' => true, // Greek/Coptic
            '\u{0400}'..='\u{04FF}' => true, // Cyrillic
            '\u{0500}'..='\u{052F}' => true, // Cyrillic Supplement
            '\u{0530}'..='\u{058F}' => true, // Armenian
            '\u{0590}'..='\u{05FF}' => true, // Hebrew
            '\u{0600}'..='\u{06FF}' => true, // Arabic
            '\u{0700}'..='\u{074F}' => true, // Syriac
            _ => false,
        }
    };
}

#[macro_export]
macro_rules! alpha_numeric_char {
    ($c: expr) => {
        $crate::alpha_char!($c) || $crate::decimal_digit_char!($c)
    };
}

#[macro_export]
macro_rules! backslash_char {
    ($c: expr) => {
        $c == '\\'
    };
}

#[macro_export]
macro_rules! back_quote_char {
    ($c: expr) => {
        $c == '`'
    };
}

#[macro_export]
macro_rules! binary_digit_char {
    ($c: expr) => {
        $c >= '0' && $c <= '1'
    };
}

#[macro_export]
macro_rules! capital_letter_char {
    ($c: expr) => {
        ('A'..='Z').contains(&$c)
    };
}

#[macro_export]
macro_rules! comment_1_char {
    ($c: expr) => {
        $c == '/'
    };
}

#[macro_export]
macro_rules! comment_2_char {
    ($c: expr) => {
        $c == '*'
    };
}

#[macro_export]
macro_rules! cut_char {
    ($c: expr) => {
        $c == '!'
    };
}

#[macro_export]
macro_rules! decimal_digit_char {
    ($c: expr) => {
        ('0'..='9').contains(&$c)
    };
}

#[macro_export]
macro_rules! decimal_point_char {
    ($c: expr) => {
        $c == '.'
    };
}

#[macro_export]
macro_rules! double_quote_char {
    ($c: expr) => {
        $c == '"'
    };
}

#[macro_export]
macro_rules! end_line_comment_char {
    ($c: expr) => {
        $c == '%'
    };
}

#[macro_export]
macro_rules! exponent_char {
    ($c: expr) => {
        $c == 'e' || $c == 'E'
    };
}

#[macro_export]
macro_rules! graphic_char {
    ($c: expr) => ($crate::char_class!($c, ['#', '$', '&', '*', '+', '-', '.', '/', ':',
                                    '<', '=', '>', '?', '@', '^', '~']))
}

#[macro_export]
macro_rules! graphic_token_char {
    ($c: expr) => {
        $crate::graphic_char!($c) || $crate::backslash_char!($c)
    };
}

#[macro_export]
macro_rules! hexadecimal_digit_char {
    ($c: expr) => {
        ('0'..='9').contains(&$c) || ('A'..='F').contains(&$c) || ('a'..='f').contains(&$c)
    };
}

#[macro_export]
macro_rules! layout_char {
    ($c: expr) => {
        $crate::char_class!($c, [' ', '\n', '\t', '\u{0B}', '\u{0C}'])
    };
}

#[macro_export]
macro_rules! meta_char {
    ($c: expr) => {
        $crate::char_class!($c, ['\\', '\'', '"', '`'])
    };
}

#[macro_export]
macro_rules! new_line_char {
    ($c: expr) => {
        $c == '\n'
    };
}

#[macro_export]
macro_rules! octal_digit_char {
    ($c: expr) => {
        ('0'..='7').contains(&$c)
    };
}

#[macro_export]
macro_rules! octet_char {
    ($c: expr) => {
        ('\u{0000}'..='\u{00FF}').contains(&$c)
    };
}

#[macro_export]
macro_rules! prolog_char {
    ($c: expr) => {
        $crate::graphic_char!($c)
            || $crate::alpha_numeric_char!($c)
            || $crate::solo_char!($c)
            || $crate::layout_char!($c)
            || $crate::meta_char!($c)
    };
}

#[macro_export]
macro_rules! semicolon_char {
    ($c: expr) => {
        $c == ';'
    };
}

#[macro_export]
macro_rules! sign_char {
    ($c: expr) => {
        $c == '-' || $c == '+'
    };
}

#[macro_export]
macro_rules! single_quote_char {
    ($c: expr) => {
        $c == '\''
    };
}

#[macro_export]
macro_rules! small_letter_char {
    ($c: expr) => {
        ('a'..='z').contains(&$c)
    };
}

#[macro_export]
macro_rules! solo_char {
    ($c: expr) => {
        $crate::char_class!($c, ['!', '(', ')', ',', ';', '[', ']', '{', '}', '|', '%'])
    };
}

#[macro_export]
macro_rules! space_char {
    ($c: expr) => {
        $c == ' '
    };
}

#[macro_export]
macro_rules! symbolic_control_char {
    ($c: expr) => {
        $crate::char_class!($c, ['a', 'b', 'f', 'n', 'r', 't', 'v', '0'])
    };
}

#[macro_export]
macro_rules! symbolic_hexadecimal_char {
    ($c: expr) => {
        $c == 'x'
    };
}

#[macro_export]
macro_rules! variable_indicator_char {
    ($c: expr) => {
        $c == '_'
    };
}