[Compose] 14. Build curried functions
We see what it means to curry a function, then walk through several examples of curried functions and their use cases.
For example we have an 'add' function:
const add = (x, y) => x + y;
const inc = y => add(, y);
inc(2)
//
We want to conver it to using curry function, the way we do it is by function another function inside add function:
const add = x => y => x + y;
SO the first time we call add(), it will remember the value we passed in:
const inc = add(); // now x = 1
But the function won't be run until we pass in second param:
const res = inc(); // now y = 2
console.log(res) //
----------
Of course, previous example is not that useful, there is another example:
const modulo = dvr => dvd => dvd % dvr;
const isOdd = modulo(); // dvr = 2;
const res1 = isOdd(); //dvd = 7
const res2 = isOdd(); //dvd = 4
console.log(res1) //
console.log(res2) //
Exmaple2:
const modulo = dvr => dvd => dvd % dvr;
const isOdd = modulo(); // dvr = 2;
const filter = pred => ary => ary.filter(pred);
const getAllOdds = filter(isOdd);
const res = getAllOdds([,,,,]);
console.log(res) //[1, 3, 5]
Example3:
const replace = regex => replaceWith => str =>
str.replace(regex, replaceWith); const censor = replace(/[aeiou]/ig)('*'); // [aeiou] --> regex, replaceWith --> *
const res = censor('Hello World');
console.log(res); //"H*ll* W*rld"
Example 4:
const map = fn => ary => ary.map(fn);
const replace = regex => replaceWith => str =>
str.replace(regex, replaceWith);
const censor = replace(/[aeiou]/ig)('*'); // [aeiou] --> regex, replaceWith --> *
const censorAll = map(censor);
const res = censorAll(["Hello", "World"]);
console.log(res); //["H*ll*", "W*rld"]
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