Counting occurrences of a substring in a string

[xwu (Xiaodi Wu)]

Count(of:) and contains(other:) for Collection

Introduction This is inspired by the proposal of adding count methods to Sequence. Apart from count(of: Element) and count(where:), there is another count method and, in addition, a contains method that I consider a sensible addition to Collection. Methods count<T: Collection>(of other: T, overlapping: Bool) -> Int where T.Element == Element Returns the number of occurrences of the given subcollection in the collection. When overlapping is true, overlapping occurrences are also counted. con…