Look into console.

Need implement:

1. Input commands from this window.
2. Output to this window.
3. More methods.

Input commands:

        run("do(define(total, 0),",
            " define(count, 1),",
            " while(<(count, 11),",
            " do(define(total, +(total, count)),",
            " define(count, +(count, 1)))),",
            " print(total))");

        run("do(define(plusOne, fun(a, +(a, 1))),",
            " print(plusOne(10)))");

        run("do(define(pow, fun(base, exp,",
            " if(==(exp, 0),",
            " 1,",
            " *(base, pow(base, -(exp, 1)))))),",
            " print(pow(2, 10)))");
        
        run("do(print(element(array(1, 2, 3), 1)))");
        
        run("do(define(sum, fun(array,",
            " do(define(i, 0),",
            " define(sum, 0),",
            " while(<(i, length(array)),",
            " do(define(sum, +(sum, element(array, i))),",
            " define(i, +(i, 1)))),",
            " sum))),",
            " print(sum(array(1, 2, 3))))");
        
        run("do(define(f, fun(a, fun(b, +(a, b)))),",
            " print(f(4)(5)))");

        

Results: