next()

in packages/fbjs/src/core/enumerate.js [100:131]

• 26 lines of code
• 6 McCabe index (conditional complexity)

      next() {
        if (this._iteratedString == null) {
          return {value: undefined, done: true};
        }

        let index = this._nextIndex;
        let s = this._iteratedString;
        let len = s.length;

        if (index >= len) {
          this._iteratedString = undefined;
          return {value: undefined, done: true};
        }

        let ret;
        let first = s.charCodeAt(index);

        if (first < 0xD800 || first > 0xDBFF || index + 1 === len) {
          ret = s[index];
        } else {
          let second = s.charCodeAt(index + 1);
          if (second < 0xDC00 || second > 0xDFFF) {
            ret = s[index];
          } else {
            ret = s[index] + s[index + 1];
          }
        }

        this._nextIndex = index + ret.length;

        return {value: ret, done: false};
      }