YooMoney Functional Swift library
Functor
Transfer A<T> -> A<U> with T -> U
let ƒ: (T) -> U
let a: T? = T()
let b: U? = ƒ <^> a
let c: U? = U() <^ a
let d: U? = a ^> U()Applicative
Applicative is a wrapper, that can apply wrapped function to wrapped value.
Applicative transfer A<T> -> A<U> with A<(T) -> U>.
let ƒ: Optional<(T) -> U>
let a: T? = T()
let b: U? = ƒ <*> aApplicative also has several auxiliary functions for applying a function multiple arguments to the wrapped arguments:
liftA2: ((T, U) -> V, A<T>, A<U>) -> A<V>
liftA3: ((T, U, V) -> W, A<T>, A<U>, A<V>) -> A<W>Monad
Transfer A<T> -> A<U> with T -> A<U>
let ƒ: (T) -> U?
let a: T? = T()
let b: U? = ƒ -<< a
let c: U? = a >>- ƒMonoid
Type which can be composed
struct Sum {
let number: Integer
init(_ number: Integer) {
self.number = number
}
}
extension Sum: Monoid {
static func mempty() -> Sum {
return Sum(0)
}
func mappend(_ monoid: Sum) -> Sum {
return Sum(number + monoid.number)
}
}
let numbers = [5, 8, 9, 0, 1, 7, 8]
let sum = numbers.map(Sum.init).mconcat().number // = 38