Reader monad in Swift, inspired by implemention with Scala.
Reader
is a wrapper for function that take some Input
and produce Element
.
// init(_:)
let reader = Reader<Int, Int> { $0 + 2 }
// execute(_:)
reader.execute(1) // 3
reader.execute(2) // 4
// map(_:)
reader
.map { $0 * 2 }
.execute(3) // 10
// flatMap(_:)
reader
.flatMap { i1 in Reader<Int, Int> { i2 in i1 * i2 } }
.execute(4) // 24
Simple and static Dependency Injection is possible with Reader
example: Playground
Add following line into your Cartfile and run carthage update
.
github "to4iki/Reader"
Add following line into your Package.swift and run swift build
.
dependencies: [
.Package(url: "https://github.com/to4iki/Reader.git", majorVersion: 0)
]