commit_porto_functional_javascript.js

const sum = (a, b) => a + b;

const not = (value) => !value;

const isEven = (number) => number % 2 == 0;

console.log("sum(4, 2) == " + sum(4,2));

console.log("not(true) == " + not(true));

console.log("isEven(4) == " + isEven(4));
console.log("isEven(7) == " + isEven(7));

const twice = (fn) => (a) => fn(a, a);
const double = twice(sum);
console.log("double(5) == " + double(2));
console.log("double(5) == " + double(5));
console.log("double(5) == " + double(10));

const apply = (fn1) => (fn2) => (number) => fn1(fn2(number));

const negate = apply(not);
const isOdd = negate(isEven);
console.log("isOdd(4) == " + isOdd(4));
console.log("isOdd(7) == " + isOdd(7));

console.log("isOdd(4) == " + apply(not)(isEven)(4));
console.log("isOdd(7) == " + apply(not)(isEven)(7));

/*
 $.get("/getUser", {
 userName: "maria"
 }, (data) => setPageTitle(data.fullName));

 // user properties library
 const getFullName = (fn) => (data) => fn(data.fullName);


 $.get("/getUser", { userName: "maria"  }, getFullName(setPageTitle));

 */

const sum2 = (a) => (b) => a + b;
console.log("sum2(4)(2) == " + sum2(4)(2));

add10 = sum2(10);

console.log("add10(5) == " + add10(5));

const biggerThan = (a) => (b) => a < b;

console.log("biggerThan(1)(10) == " + biggerThan(1)(10));


const map = (fn) => (list) => {
    let newList = [];
    for( let i = 0; i < list.length; i++) {
        newList.push(fn(list[i]));
    }
    return newList;
};

console.log("map(add10)([1,2,3]) == " + map(add10)([1,2,3]));

const add10ToList = map(add10);
console.log("add10ToList([5,10,15]) == " + add10ToList([5,10,15]));

const reduce = (fn) => (list) => {
    let result = fn(list[0], list[1]);
    for( let i = 2; i < list.length; i++) {
        result = fn(result, list[i]);
    }
    return result;
};

console.log("reduce(sum)([1,2,3,4,5]) == " + reduce(sum)([1,2,3,4,5]));
const sumAll = reduce(sum);
console.log("sumAll([1,2,3,4,5]) == " + sumAll([1,2,3,4,5]));

const filter = (fn) => (list) => {
    let newList = [];
    for(let i = 0; i < list.length; i++) {
        if(fn(list[i])) {
            newList.push(list[i]);
        }
    }
    return newList;
};

const getOdd = filter(isOdd);
console.log("getOdd([1,2,3,4,5]) == " + getOdd([1,2,3,4,5]));

talk given in http://commitporto.com/ 2016