Class Seq

src/Seq.js:24–85

import isArrayLike from './utils/isArrayLike';

export class Seq extends Collection {
  constructor(value) {
    // eslint-disable-next-line no-constructor-return
    return value === undefined || value === null
      ? emptySequence()
      : isImmutable(value)
        ? value.toSeq()
        : seqFromValue(value);
  }

  toSeq() {
    return this;
  }

  toString() {
    return this.__toString('Seq {', '}');
  }

  cacheResult() {
    if (!this._cache && this.__iterateUncached) {
      this._cache = this.entrySeq().toArray();
      this.size = this._cache.length;
    }
    return this;
  }

  // abstract __iterateUncached(fn, reverse)

  __iterate(fn, reverse) {
    const cache = this._cache;
    if (cache) {
      const size = cache.length;
      let i = 0;
      while (i !== size) {
        const entry = cache[reverse ? size - ++i : i++];
        if (fn(entry[1], entry[0], this) === false) {
          break;
        }
      }
      return i;
    }
    return this.__iterateUncached(fn, reverse);
  }

  // abstract __iteratorUncached(type, reverse)

  __iterator(type, reverse) {
    const cache = this._cache;
    if (cache) {
      const size = cache.length;
      let i = 0;
      return new Iterator(() => {
        if (i === size) {
          return iteratorDone();
        }
        const entry = cache[reverse ? size - ++i : i++];
        return iteratorValue(type, entry[0], entry[1]);
      });