Lazy pipeline API using wrapped iterators and generators to pump values through the chain

pipe.js

function Pipe(sequence) {
  const wrappedIterator = sequence[Symbol.iterator]();
  this.next = wrappedIterator.next.bind(wrappedIterator);
}

Pipe.step = function(generator) {
  return new Pipe({
    [Symbol.iterator]: generator
  });
}

Pipe.prototype[Symbol.iterator] = function() {
  return this;
}

Pipe.prototype.map = function(fn) {
  const sequence = this;

  return Pipe.step(function*() {
    for (let entry of sequence) {
      yield fn(entry);
    }
  });
}

Pipe.prototype.filter = function(fn) {
  const sequence = this;

  return Pipe.step(function*() {
    for (let entry of sequence) {
      if (fn(entry)) yield entry;
    }
  });
}

Pipe.prototype.take = function(number) {
  const sequence = this;

  return Pipe.step(function*() {
    for (let index=0; index < number; index++) {
      yield sequence.next().value;
    }
  })
}

Pipe.prototype.all = function() {
  return [...this];
}

const evenValues = (x) => (x % 2) == 0;
const squareValues = (x) => x * 2;

const filteredPipeline = new Pipe([1,2,3,4]).filter(evenValues);

console.log("expected: 2", `actual: ${filteredPipeline.next().value}`);
console.log("expected: 4", `actual: ${filteredPipeline.next().value}`);

const squareEvenValues = new Pipe([1,2,3,4,5,6,7,8,9]).filter(evenValues).map(squareValues);

console.log("expected: 4,8,12,16", `actual: ${squareEvenValues.all()}`);

const firstTwoSquared = new Pipe([1,2,3,4,5,6]).filter(evenValues).map(squareValues).take(2);

console.log("expected: 4,8", `actual: ${firstTwoSquared.all()}`);