Memoization

A lightweight and generic memoization utility for Swift. Supports multiple parameter functions using parameter packs.

Requirements

Swift 5.9+

Installation

Swift Package Manager

Add this package to your Package.swift:

let package = Package(
  name: "YourProject",
  dependencies: [
    .package(url: "https://github.com/Jaesung-Jung/Memoization.git", .upToNextMajor(from: "1.0"))
  ],
  targets: [
    .target(
      name: "YourProject",
      dependencies: [
        .product(name: "Memoization", package: "Memoization")
      ]
    )
  ]
)

Usage

Parameterless function

let memoized = memoize {
    print("Computing…")
    return 42
}

print(memoized()) // First call: prints "Computing…"
print(memoized()) // Subsequent calls: returns cached value, no print

Function with parameters

let sum: (Int, Int) -> Int = memoize { a, b in
    print("Computing sum: \(a), \(b)")
    return a + b
}

print(sum(1, 2)) // First call with (1, 2): prints
print(sum(1, 2)) // Cache
print(sum(2, 3)) // First call with (2, 3): prints

Fibonacci example

func fibonacci(_ n: Int) -> Int {
  guard n > 1 else {
    return n
  }
  return fibonacci(n - 1) + fibonacci(n - 2)
}

let fibo = memoize(fibonacci)
let operatedValue = fibo(10)
let cacheValue = fibo(10)

print(operatedValue) // 55
print(cacheValue)    // 55

License

MIT license. See LICENSE for details.