(() => {
    "use strict";

    // -------------- MULTIPLICATION TABLE ---------------

    // multTable :: Int -> Int -> [[String]]
    const multTable = m => n => {
        const xs = enumFromTo(m)(n);

        return [
            ["x", ...xs],
            ...xs.flatMap(
                x => [
                    [x, ...xs.flatMap(
                        y => y < x ? (
                            [""]
                        ) : [`${x * y}`]
                    )]
                ]
            )
        ];
    };

    // ---------------------- TEST -----------------------

    // main :: () -> IO String
    const main = () =>
        wikiTable({
            class: "wikitable",
            style: [
                "text-align:center",
                "width:33em",
                "height:33em",
                "table-layout:fixed"
            ].join(";")
        })(
            multTable(1)(12)
        );

    // ---------------- GENERIC FUNCTIONS ----------------

    // enumFromTo :: Int -> Int -> [Int]
    const enumFromTo = m => n =>
        n >= m ? Array.from({
            length: Math.floor(n - m) + 1
        }, (_, i) => m + i) : [];


    // ------------------- FORMATTING --------------------

    // wikiTable :: Dict -> [[a]] -> String
    const wikiTable = opts =>
        rows => {
            const
                style = ["class", "style"].reduce(
                    (a, k) => k in opts ? (
                        `${a}${k}="${opts[k]}" `
                    ) : a, ""
                ),
                body = rows.map((row, i) => {
                    const
                        cells = row.map(
                            x => `${x}` || " "
                        ).join(" || ");

                    return `${i ? "|" : "!"} ${cells}`;
                }).join("\n|-\n");

            return `{| ${style}\n${body}\n|}`;
        };

    //  MAIN ---
    return main();
})();