TheNamesJamesW

extension Collection {
    func dictionary<K, V>(transform:(_ element: Iterator.Element) -> [K : V]) -> [K : V] {
        var dictionary = [K : V]()
        self.forEach { element in
            for (key, value) in transform(element) {
                dictionary[key] = value
            }
        }
        return dictionary
    }

TheNamesJamesW

/**
 Defines a filter that can be applied on a `Sequence` instance but stored (and passed around) independently.
 
 Useful if switching filters frequently, creating dynamic subsets of a given dataset and passing between abstraction levels (i.e. View level could create this and pass to the Model)
 
 Example:
 ```
 let strings = ["c", "b", "b", "b", "a"]
 var predicate: Filter<String, [String]>
 

TheNamesJamesW

// For-in but only enumerate values of a certain type
let things = [1, 2, "three"]
for case let number as Int in things {
  print(number)
}
// Prints:
// 1
// 2