Call a function n times with its output

/// Calls a function n times passing the result of each call into the next call.
///
/// - Parameters:
///   - function: A function that takes T and returns T. It will be called multiple times and produce the result.
///   - initialInput: The initial input to pass into the function.
///   - repetitions: The number of times the function has to be called.
/// - Returns: Returns the result of consecutive calls to the given functions.
func call<T>(_ function: @escaping (T) -> T?, initialInput: T, repetitions: Int) -> T? {
    var seq = sequence(first: initialInput, next: function)
    
    var result: T?
    
    //we call next() n+1 times because otherwise the first call would result in the initial input being the output.
    for _ in 0..<(repetitions + 1) {
        result = seq.next()
    }
    
    return result
}