the-wheel

Usage

npm install the-wheel

For

Let's say you wanted to write this for loop without iteration:

let sum = 0;
for(let i = 0; i < 10; i = i + 1) {
  sum = sum + i;
}

Now you can write this "clearer" implementation instead:

const { For } = require('the-wheel');
 
let sum = 0;
 
function condition(iterator) {
  return iterator < 10;
}
 
function step(iterator) {
  return iterator + 1;
}
 
function body(iterator) {
  sum = sum + iterator;
}
 
For(0, condition, step, body);

Or if you want to write it more compactly in a form similar to an actual for loop:

const { For } = require('the-wheel');
 
let sum = 0;
For(0, i => i < 10, i => i += 1, i => {
  sum += i;
});

What if you want to reflect the break and continue implemented in native loops? Given that the body functions don't need return anything, you take advantage of this by return-ing special cases.

A simple return is the same as a native continue:

// only log even numbers
 
for(let i = 0; i < 10; i ++) {
  if(i % 2 != 0) {
    continue;
  }
 
  console.log(i);
}
 
For(0, i => i < 10, i => i + 1, i => {
  if(i % 2 != 0) {
    return;
  }
 
  console.log(i);
});

You can also implement a break in this way by returning something from your body function.

// linear search
const target = 'Carmen Sandiego';
let where;
 
for(let i = 0; i < world.length; i ++) {
  if(world[i] === target) {
    where = i;
    break;
  }
}
 
For(0, i => i < world.length; i => i + 1, i => {
  if(world[i] === target) {
    where = i;
    return 1;
  }
});

While

While has a very similar usage to For

let sum = 0;
let i = 0;
 
while(i < 10) {
  sum += i;
}

Can in turn be written as follows

const { While } = require('the-wheel');
 
let sum = 0;
let i = 0;
 
function condition() {
  return i < 10;
}
 
function body() {
  sum += i;
  i += 1;
}
 
While(condition, body);

Or more succinctly as

While(() => i < 10, () => {
  sum += i;
  i += 1;
});

You can implement break and continue in the same manner as a For loop by performing return in your body function.

Tests

npm test