Function takeWhileFactory

src/Operations.js:506–544

(collection, predicate, context)

}

export function takeWhileFactory(collection, predicate, context) {
  const takeSequence = makeSequence(collection);
  takeSequence.__iterateUncached = function (fn, reverse) {
    if (reverse) {
      return this.cacheResult().__iterate(fn, reverse);
    }
    let iterations = 0;
    collection.__iterate(
      (v, k, c) =>
        predicate.call(context, v, k, c) && ++iterations && fn(v, k, this)
    );
    return iterations;
  };
  takeSequence.__iteratorUncached = function (type, reverse) {
    if (reverse) {
      return this.cacheResult().__iterator(type, reverse);
    }
    const iterator = collection.__iterator(ITERATE_ENTRIES, reverse);
    let iterating = true;
    return new Iterator(() => {
      if (!iterating) {
        return iteratorDone();
      }
      const step = iterator.next();
      if (step.done) {
        return step;
      }
      const entry = step.value;
      const k = entry[0];
      const v = entry[1];
      if (!predicate.call(context, v, k, this)) {
        iterating = false;
        return iteratorDone();
      }
      return type === ITERATE_ENTRIES ? step : iteratorValue(type, k, v, step);
    });
  };
  return takeSequence;
}

export function skipWhileFactory(collection, predicate, context, useKeys) {
  const skipSequence = makeSequence(collection);