rotated method

Iterable<E> rotated(int n)

Creates an Iterable with the rotated values.

This method does not modify the original list, it returns a new Iterable (similarly how reversed returns an Iterable.

final values = [1, 2, 3, 4, 5, 6, 7, 8, 9];
// It returns an Iterable!
print(values.rotated(3).take(4)); // [7, 8, 9, 1]

// rotated doesn't modify the list!
print(values); // It is still: [1, 2, 3, 4, 5, 6, 7, 8, 9]

If you want to rotate in-place, use the rotate method.

Positive n rotates to the right. Negative n rotates to the left. When n % length is equal to zero, the list will not be rotated.

// right
print([1, 2, 3, 4].rotated(1).toList()); // [4, 1, 2, 3]

// left
print([1, 2, 3, 4].rotated(-1).toList()); // [2, 3, 4, 1]

// noop
print([1, 2, 3, 4].rotated(4).toList()); // [1, 2, 3, 4]

Implementation

Iterable<E> rotated(int n) sync* {
  final length = this.length;
  for (final i in range(length)) {
    yield this[(i - n) % length];
  }
}