I'm experimenting with writing Swifts .filter function and have run into some confusion. I'm essentially trying to modify this function:
func anotherFilter<T>(elements: [T], predicate: (T) -> Bool) -> [T] { var filteredArray = [T]() for element in elements { if predicate(element) { filteredArray += [element] } } return filteredArray } Into an extension:
extension Array { func anotherFilter<T>(elements: [T], predicate: (T) -> Bool) -> [T] { var filteredArray = [T]() for element in elements { if predicate(element) { filteredArray += [element] } } return filteredArray } } Of course this version of the extension works but it requires that you pass the object in which doesn't make sense:
self.coords.anotherFilter (coords) { self.someOperation(coords, op: $0) } What I've Tried
Obviously, what I'd like to achieve is something like this:
extension Array { func anotherFilter <T>(predicate: (T) -> Bool) -> [T] { var filteredArray = [T]() for item in self { if predicate(item) { filteredArray.append(item) } } } } But this returns an error:
Cannot invoke 'predicate' with an argument list of type '(Element)'
Question
How do I pass the object (in this case coords) into my extension without parameterizing it? Deeper explanations are most welcome.
