class Tokens {
    static template makeTokenType(string ident, string category, string match = null) {
        const char[] makeTokenType =
            "static immutable TokenType " ~ ident ~ ";" ~
            "static this() {" ~
            "    " ~ ident ~ " = cast(immutable) TokenType(TokenCategory." ~ category ~ ", \"" ~ ident ~ "\"" ~ (match ? ", \"" ~ match ~ "\"" : "") ~ ");" ~
            "}";
    }

    static TokenType[string] keywords;
    static TokenType[string] operators;

    /* Identifiers */
    mixin(makeTokenType!("IDENTIFIER",    "IDENTIFIER"));

    /* Keywords */
    mixin(makeTokenType!("LOCAL",         "KEYWORD",  "local"));
    mixin(makeTokenType!("FUNCTION",      "KEYWORD",  "function"));
    mixin(makeTokenType!("IF",            "KEYWORD",  "if"));
    mixin(makeTokenType!("ELSE",          "KEYWORD",  "else"));
    mixin(makeTokenType!("WHILE",         "KEYWORD",  "while"));
    mixin(makeTokenType!("BREAK",         "KEYWORD",  "break"));
    mixin(makeTokenType!("RETURN",        "KEYWORD",  "return"));
    mixin(makeTokenType!("FOR",           "KEYWORD",  "for"));
    mixin(makeTokenType!("TRUE",          "KEYWORD",  "true"));
    mixin(makeTokenType!("FALSE",         "KEYWORD",  "false"));

    /* Operators */
    mixin(makeTokenType!("PLUS",          "OPERATOR", "+"));
    mixin(makeTokenType!("ASTERISK",      "OPERATOR", "*"));
    mixin(makeTokenType!("DASH",          "OPERATOR", "-"));
    mixin(makeTokenType!("FSLASH",        "OPERATOR", "/"));
    mixin(makeTokenType!("EQUALS",        "OPERATOR", "="));
    mixin(makeTokenType!("EQUALS_EQUALS", "OPERATOR", "=="));
    mixin(makeTokenType!("LT",            "OPERATOR", "<"));
    mixin(makeTokenType!("LTE",           "OPERATOR", "<="));
    mixin(makeTokenType!("GT",            "OPERATOR", ">"));
    mixin(makeTokenType!("GTE",           "OPERATOR", ">="));
    mixin(makeTokenType!("INEQUAL",       "OPERATOR", "!="));
    mixin(makeTokenType!("LBRACE",        "OPERATOR", "{"));
    mixin(makeTokenType!("RBRACE",        "OPERATOR", "}"));
    mixin(makeTokenType!("LPAREN",        "OPERATOR", "("));
    mixin(makeTokenType!("RPAREN",        "OPERATOR", ")"));
    mixin(makeTokenType!("NOT",           "OPERATOR", "!"));

    /* Literals */
    mixin(makeTokenType!("NUMBER",        "LITERAL"));
    mixin(makeTokenType!("STRING",        "LITERAL"));
}