README.md

From

var fib_6 = {
  v: Int -> Int  in
  if v <= 1  { return v }
  return ???(v - 1) + ???(v - 2)
}(6)

to

  🤫 { (v, fib) -> Int in
      if v <= 1 { return v }
      return fib(v - 1) + fib(v - 2)
  }(6)

🤫.swift

struct 🤫<IN, OUT> {
    init(function: @escaping (IN, 🤫<IN, OUT>) -> OUT) {
        self.closure = {
            (_in: IN, `self`: 🤫<IN, OUT>) in
            try function(_in, self)
        }
    }

    let closure: (IN, 🤫<IN, OUT>) -> OUT
    func callAsFunction(_ in: IN) -> OUT {
         closure(`in`, self)
    }
}

🤫Tests.swift

class 🤫Tests: XCTestCase {
    func test() throws {
          XCTAssertEqual(
            8,

            🤫 { (v, fib) -> Int in
                if v <= 1 { return v }
                return fib(v - 1) + fib(v - 2)
            }(6))
    }
}