replaceRange method

view source

void replaceRange (int start, int end, Iterable<T> newContents) inherited

Implementation

void replaceRange(int start, int end, Iterable<E> newContents) {
  RangeError.checkValidRange(start, end, this.length);
  if (start == this.length) {
    addAll(newContents);
    return;
  }
  if (newContents is! EfficientLengthIterable) {
    newContents = newContents.toList();
  }
  int removeLength = end - start;
  int insertLength = newContents.length;
  if (removeLength >= insertLength) {
    int insertEnd = start + insertLength;
    this.setRange(start, insertEnd, newContents);
    if (removeLength > insertLength) {
      _closeGap(insertEnd, end);
    }
  } else if (end == this.length) {
    int i = start;
    for (E element in newContents) {
      if (i < end) {
        this[i] = element;
      } else {
        add(element);
      }
      i++;
    }
  } else {
    int delta = insertLength - removeLength;
    int oldLength = this.length;
    int insertEnd = start + insertLength; // aka. end + delta.
    for (int i = oldLength - delta; i < oldLength; ++i) {
      add(this[i > 0 ? i : 0]);
    }
    if (insertEnd < oldLength) {
      this.setRange(insertEnd, oldLength, this, end);
    }
    this.setRange(start, insertEnd, newContents);
  }
}