//ex 1
console.log("Exercise 1");

add = (a, b) => a + b;
mul = (a, b) => a * b;

console.log(add(4, 7));
console.log(mul(4, 7));

//ex 2
console.log("Exercise 2");

const identify = function(argument){
    return function(){
        return argument;
    }
};

let idf = identify(5);

console.log(idf());

//ex 3
console.log("Exercise 3");

let addf = function(a){
    return function(b){
        return a + b;
    }
}

console.log(addf(4)(3));

//ex 4
console.log("Exercise 4");

const applyf = function(func){
    return function(a){
        return function(b){
            return func(a, b);
        }
    }
}

addf = applyf(add);
console.log(addf(10)(3));

addf = applyf(mul);
console.log(addf(10)(3));

//ex 5
console.log("Exercise 5");

const curry = function(func, first){
    return function(second){
        return func(first, second);
    }
}

const add3 = curry(add, 3);

console.log(add3(2));
console.log(curry(mul, 5)(10));

//ex 6
console.log("Exercise 6");

const twice = function(func){
    return function(arg){
        return func(arg, arg);
    }
}

const double = twice(add);
const square = twice(mul);

console.log(double(12));
console.log(square(12));

//ex 7
console.log("Exercise 7");

const composeu = function(first, second){
    return function(arg){
        return second(first(arg));
    }
}

console.log(composeu(double, square)(3));

//ex 8
console.log("Exercise 8");

function composeb(first, second){
    return function(a, b, c){
        return second(first(a, b), c);
    }
}

console.log(composeb(add, mul)(2, 3, 5));

//ex 9
console.log("Exercise 9");

const counterf = function(val){
    return {
        _value : val,
        inc : function(){
            this._value++;
            return this._value;
        },
        dec : function(){
            this._value--;
            return this._value;
        }
    }
}

const counter = counterf(10);
console.log(counter.inc());
console.log(counter.dec());